Publications
In press:
De Klerk, P.: Vegetation history, mire development and human impact in and around the Tollense Valley near Neubrandenburg (Mecklenburg-Vorpommern, NE Germany): two pollen diagrams from the legacy of Klaus Kloss. In: Tod im Tollensetal 2 (working title).
2023:
Ramezani, E., De Klerk, P., Naqinezhad, A., Theuerkauf, M. & Joosten, H.: Long-term dynamics of Oriental beech (Fagus orientalis Lipsky) stands in the Hyrcanian forests of northern Iran. Review of Palaeobotany and Palynology 312: 104871. doi: 10.1016/j.revpalbo.2023.104871
2022:
De Klerk, P.: May your reeds be great reeds – a collection of essays on reedland texts and pictures from ancient cultures. Proceedings of the Greifswald Mire Centre 02/2022, 43 p.
De Klerk, P.: Peatland prose from the past: Ancient Egyptian camouflaged mires in the works of Diodorus of Sicily (1st century BCE) and Frontinus (c. 40-103 CE). IMCG Bulletin 2022-1: Jan. – Febr. 2022: 4-6.
De Klerk, P., Hettinger, J., Musäus, I. & Joosten, H.: Zitternde Böden und brennender Schlamm: die Wahrnehmung von Moor und Torf bei den Römern. TELMA 52: 109-128.
De Klerk, P., Musäus, I. & Joosten, H.: Feuchtgebiete in Mythos und Religion alter Kulturen: eine Einführung. TELMA 52: 91-108.
De Klerk, P., Tietz, O. & Joosten, H.: Paläoökologische Forschungen im Dubringer Moor bei Hoyerswerda (Sachsen): eine Neubearbeitung alter Daten. Berichte der naturforschenden Gesellschaft der Oberlausitz 30: 131-148.
2021:
De Klerk, P.: Peatland poetry from the past: the headgear of river gods in the works of Virgil and Ovid. IMCG Bulletin 2021-2: March – Apr. 2021: 5-7.
De Klerk, P.: Peatland prose from the past: The displeasing land of Cabul (NW Israel). IMCG Bulletin 2021-6: Nov – Dec 2021: 18-21.
De Klerk, P. & Joosten, H.: The fluvial landscape of lower Mesopotamia: an overview of geomorphology and human impact. IMCG Bulletin 2021-3: May – June 2021: 6-20.
2020:
De Klerk, P., Bobrov, A., Theuerkauf, M. & Joosten, H.: Short-distance distribution patterns of testate amoebae in an arctic ice-wedge polygon mire (Berelekh-Indigirka lowlands, NE Siberia). Polar Biology 43: 1321-1340. doi: 10.1007/s00300-020-02711-5
De Klerk, P., Musäus, I. & Joosten, H.: Famicose peatlands and ungulate hoof diseases: on the meaning of a word from ‘On the meaning of words’ (Festus, 2nd century CE; Paulus Diaconus, 8th century CE). Mires and Peat 26, Article 22. doi: 10.19189/MaP.2020.OMB.StA.2018
2019:
De Klerk, P.: Peatland poetry from the past: The Calydonian boar in the Metamorphoses by Ovid (43 BCE – 17/18 CE). IMCG Bulletin 2019-06 (November-December 2019): 13-14.
De Klerk, P.: Peatland prose from the past: the trembling soils of Pliny the Elder (23-79 CE). IMCG Bulletin February-March 2019: 3.
De Klerk, P.: Peatland prose from the past: the indulgent and exorbitant mires of St. Ambrose (340-397 CE). IMCG Bulletin April 2019: 2-3.
De Klerk, P.: Peatland prose from the past: the Sudd in the south. IMCG Bulletin 2019-05 (August-October 2019): 7-12.
De Klerk, P. & Joosten, H.: How ancient cultures perceived mires and wetlands (3000 BCE – 500 CE): an introduction. IMCG Bulletin 2019-04 (May-July 2019): 4-15.
2018:
De Klerk, P.: The roots of pollen analysis: the road to Lennart von Post. Vegetation History and Archaeobotany 27: 393-409.
De Klerk, P. & Brumlich, M.: Pollenanalysen an Sedimenten aus dem Rangsdorfer See zur Rekonstruktion der Vegetations- und Siedlungsgeschichte im Umfeld der Glienicker Platte mit einer hohen zeitlichen Auflösung der mittleren Bronze- bis frühen römischen Kaiserzeit (ca. 1500 BC – 200 AD). In: Brumlich, M.: Frühe Eisenverhüttung bei Glienick. Siedlungs- und wirtschaftsarchäologische Forschungen zur vorrömischen Eisen- und römischen Kaiserzeit in Brandenburg. Berliner Archäologische Forschungen 17: 629-651.
De Klerk, P., Donner, N., Minke, M. & Joosten, H.: Comprehending the arctic ice-wedge polygon mire landscape using short-distance high resolution palaeoecological research. In: Sychev, V.G. & Mueller, L. (eds): Novel methods and results of landscape research in Europe, Central Asia and Siberia. Volume 1: Landscapes in the 21th century: status analyses, basic processes and research concepts. Russian Academy of Sciences FSBSI “All-Russian research institute of Agrochemistry named after D.N. Pryanishnikov”: 257-262. doi: 10.25680/6112.2018.76.43.048257-262.
2017:
De Klerk, P.: 2500 years of palaeoecology: a note on the work of Xenophanes of Colophon (circa 570-475 BCE). Journal of Geography, Environment and Earth Science International 9(4): 1-6; article no. JGEESI.32198.
De Klerk, P.: Contributions to the European Pollen Database 31. Endinger Bruch “Hoher Birkengraben” (NE Germany): from lake to carr. Grana 56: 155-157.
De Klerk P.: Contributions to the European Pollen Database 32. Endinger Bruch EB25 (NE Germany): from fen to bog. Grana 56: 158-160.
De Klerk, P., Theuerkauf, M. & Joosten, H.: Vegetation, recent pollen deposition, and distribution of some non-pollen palynomorphs in a degrading ice-wedge polygon mire complex near Pokhodsk (NE Siberia), including size-frequency analyses of pollen attributable to Betula. Review of Palaeobotany and Palynology 238: 122-143.
2016:
Behrens, E., de Klerk, P. & Joosten, H.: Records from the collapsed polygon complex MNP12 for actuo- and palaeoecological studies. In: Schirrmeister, L., Pestryakova, L., Schneider, A. & Wetterich, S. (eds.): Studies of polygons in Siberia and Svalbard. Berichte zur Polar- und Meeresforschung / Reports on Polar and Marine Research 697: 49-54.
De Klerk, P. & Joosten, H.: Vegetation history and mire development in the northwestern part of the Dubringer Moor near Hoyerswerda (Sachsen, E Germany) inferred from a pollen diagram from the legacy of Klaus Kloss. Mauritiana 30: 77-95.
Teltewskoi, A., Beermann, F., Beil, I., Bobrov, A., de Klerk, P., Lorenz, S., Lüder, A., Michaelis, D. & Joosten, H.: 4000 years of changing wetness in a permafrost polygon peatland (Kytalyk, NE Siberia): a comparative high-resolution multi-proxy study. Permafrost and Periglacial Processes 27: 76-95.
2015:
De Klerk, P., Couwenberg, J. & Joosten, H.: Pollen and macrofossils attributable to Fagopyrum in western Eurasia prior to the late Medieval: an intercontinental mystery. Palaeogeography, Palaeoclimatology, Palaeoecology 440: 1-21.
Nguyen Thuy Duong, de Klerk, P. & Joosten, H.: Presence of Camptotheca in the Red River Delta (North Vietnam) during the Holocene revealed by palynological studies. European Journal of Medicinal Plants 5: 260-271.
2014:
De Klerk, P.: Palynological research of the Vosges Mountains (NE France): a historical overview. Carolinea 72: 15-39.
De Klerk, P., Teltewskoi, A., Theuerkauf, M. & Joosten, H.: Vegetation patterns, pollen deposition and distribution of non-pollen palynomorphs in an ice-wedge polygon near Kytalyk (NE Siberia), with some remarks on Arctic pollen morphology. Polar Biology 37: 1393-1412.
Donders, T.H., Hagemans, K., Dekker, S.C., de Weger, L.A., de Klerk, P. & Wagner-Cremer, F.: Region-specific sensitivity of anemophilous pollen deposition to temperature and precipitation. PLoS ONE 9(8): e104774.
2012:
Barthelmes, A., de Klerk, P., Prager, A., Theuerkauf, M., Unterseher, M. & Joosten, H.: Expanding NPP analysis to eutrophic and forested sites: significance of NPPs in a Holocene wood peat section (NE Germany). Review of Palaeobotany and Palynology 186: 22-37.
Donner, N., Minke, M., de Klerk, P., Sofronov, R. & Joosten, H.: Patterns in polygon mires in north-eastern Yakutia, Siberia: the role of vegetation and water. The Finnish Environment 38: 19-30.
Lane, C.S., de Klerk, P. & Cullen, V.L.: A tephrochronology for the Lateglacial palynological record of the Endinger Bruch (Vorpommern, NE Germany). Journal of Quaternary Science 27: 141-149.
Nielsen, A.B., Giesecke, T., Theuerkauf, M., Feeser, I., Behre, K.-E., Beug, H.-J., Chen, S.-W., Christiansen, J., Dörfler, W., Endtmann, E., Jahns, S., de Klerk, P., Kühl, N., Latalowa, M., Odgaard, B.V., Rasmussen, P., Stockholm, J.R., Voigt, R., Wiethold, J. & Wolters, S.: Quantitative reconstructions of changes in regional openness in north-central Europe reveal new insights into old questions. Quaternary Science Reviews 47: 131-149.
Van Asch, N., Kloos, M.E, Heiri, O., de Klerk, P. & Hoek, W.Z.: The Younger Dryas cooling in northeast Germany: summer temperature and environmental changes in the Friedländer Große Wiese region. Journal of Quaternary Science 27: 531-543.
2011-2012:
De Klerk, P.: Lateglacial and Holocene vegetation development and fluvial dynamics in the Odra valley near the Slavic fortification “Grodisch” of Wiesenau (Brandenburg, E Germany) inferred from a pollen diagram from the legacy of Klaus Kloss. Veröffentlichungen zur brandenburgische Landesarchäologie 45: 131-142.
2011:
De Klerk, P., Donner, N., Karpov, N.S., Minke, M. & Joosten, H.: Short-term dynamics of a low-centred ice wedge polygon near Chokurdakh (NE Yakutia, NE Siberia) and climate change during the last ca. 1250 years. Quaternary Science Reviews 30: 3013-3031.
2010:
Barthelmes, A., Gerloff, D., de Klerk, P. & Joosten, H.: Short-term vegetation dynamics of Alnus dominated peatlands: a high resolution palaeoecological case study from western Pomerania. Folia Geobotanica 45: 279-302.
2009-2010:
De Klerk, P. & Hölzer, A.: Hochauflösende Pollendiagramme vom Tourbière Chaume Thiriet (Südvogesen, NO Frankreich) zeigen kleinräumige Muster im Pollenniederschlag während der letzten 2000 Jahre. Annales scientifiques de la réserve de biosphère transfrontalière Vosges du Nord-Pfälzerwald / Wissenschaftliches Jahrbuch des grenzüberschreitenden Biosphärenreservates Pfälzerwald-Vosges du Nord 15: 288-304.
2009:
De Klerk, P., Donner, N., Joosten, H., Karpov, N.S., Minke, M., Seifert, N. & Theuerkauf, M.: Vegetation patterns, recent pollen deposition and distribution of non-pollen palynomoprhs in a polygon mire near Chokurdakh (NE Yakutia, NE Siberia). Boreas 38: 39-58.
De Klerk, P., Haberl, A., Kaffke, A., Krebs, M., Matchutadze, I., Minke, M., Schulz, J. & Joosten, H.: Vegetation history and environmental development since ca. 6000 cal yr BP in and around Ispani 2 (Kolkheti lowlands, Georgia). Quaternary Science Reviews 28: 890-910.
Joosten, H., Krebs, M., Kaffke, A. & de Klerk, P.: Perspectives for the development of Ispani 2 and adjacent lands. Report; International Mire Conservation Group/Ernst-Moritz-ArndtUniversity Greifswald, 26 pp.
Krebs, M., Kaffke, A., de Klerk, P., Matchutadze, I. & Joosten, H.: A future for Ispani 2 (Kolkheti, Georgia) and adjacent lands. International Mire Conservation Group Newsletter 2009/2: 3-14.
Minke, M., Donner, N., Karpov, N., de Klerk, P. & Joosten, H.: Patterns in vegetation composition, surface height and thaw depth in polygon mires in the Yakutian Arctic (NE Siberia): a microtopographical characterization of the active layer. Permafrost and Periglacial Processes 20: 357-368.
2008:
De Klerk, P.: Patterns in vegetation and sedimentation during the Weichselian Late-glacial in north-eastern Germany. Journal of Biogeography 35: 1308-1322.
De Klerk, P., Helbig, H. & Janke, W.: Vegetation and environment in and around the Reinberg basin (Vorpommern, NE Germany) during the Weichselian late Pleniglacial, Lateglacial, and Early Holocene. Acta Palaeobotanica 48: 301-324.
De Klerk, P., Janke, W., Kühn, P. & Theuerkauf, M.: Environmental impact of the Laacher See Eruption at a large distance from the Volcano: integrated palaeoecological studies from Vorpommern (Germany). Palaeogeography, Palaeoclimatology, Palaeoecology 270: 196-214.
Minke, M., Donner, N., de Klerk, P., Karpov, N.S., Sofronov, R.R. & Joosten, H.: Spatial and temporal variation in carbon accumulation in a Northeast Siberian arctic polygon mire over the last millennium. Geophysical Research Abstracts 10: EGU2008-A-07425.
2007:
De Klerk, P.: Lateglacial and Holocene vegetation development around a terrestrialised bay of the Blankensee near Schönhagen (C Brandenburg, NE Germany) inferred from a pollen diagram of the late Klaus Kloss. Archiv für Naturschutz und Landschaftsforschung 46(1): 27-40.
De Klerk, P.: A pollen diagram of the “Moorer Busch” near Grevesmühlen (NW Mecklenburg, NE Germany) from the legacy of Franz Fukarek. Archiv für Naturschutz und Landschaftsforschung 46(4): 3-16.
De Klerk, P. & Joosten, H.: The difference between pollen types and plant taxa: a plea for clarity and scientific freedom. Eiszeitalter und Gegenwart/Quaternary Science Journal 56: 162-171. doi: 10.3285/eg.56.3.02, 2007
De Klerk, P., Couwenberg, J. & Joosten, H.: Short-lived vegetational and environmental change during the Preboreal in the Biebrza upper basin (NE Poland). Quaternary Science Reviews 26: 1975-1988.
Joosten, H. & de Klerk, P.: DAMOCLES: a DAshing MOnolith Cutter for fine sectioning of peats and sediments into LargeE Slices. Boreas 36: 76-81.
Joosten, H. & de Klerk, P.: In search of finiteness: the limits of fine resolution palynology of Sphagnum peat. The Holocene 17: 1023-1031.
Minke, M., Donner, N., Karpov, N.S., de Klerk, P. & Joosten, H.: Distribution, diversity, development and dynamics of polygon mires: examples from Northeast Yakutia (Siberia). Peatlands International 2007(1): 36-40.
2006:
De Klerk, P.: A pollen diagram from the Teufelssee near Potsdam (C Brandenburg, NE Germany) from the legacy of Klaus Kloss. Archiv für Naturschutz und Landschaftsforschung 45(1): 23-35.
De Klerk, P.: Lateglacial and Early Holocene vegetation history near Hennigsdorf (C Brandenburg, NE Germany): a new interpretation of palynological data of Klaus Kloss. Archiv für Naturschutz und Landschaftsforschung 45(1): 37-52.
De Klerk, P. & Helbig, H.: A pollen diagram from a kettle-hole near Horst (Vorpommern, NE Germany) covering the later part of the Weichselian Lateglacial. Zeitschrift für Geologische Wissenschaften 34: 379-387.
Joosten, H., de Klerk, P., Karkow, K. & Prager, A.: De natuurlijke context van de vindplaats. In: Pouls, J.H. & Crompvoets, H.J.G. (eds.): De gouden helm uit de Peel. Feiten en visies. Heemkundevereniging Medelo, Meijel: 53-69.
2005:
De Klerk, P.: Vegetation history and landscape development of a dune area near Uhyst (Oberlausitz, E Germany) in the Lateglacial, Early Holocene, and Late Holocene: a new interpretation of a pollen diagram of Klaus Kloss. Archiv für Naturschutz und Landschaftsforschung 44(3): 79-92.
De Klerk, P.: A pollen diagram from the Ahlbecker Seegrund (Ueckermünder Heide, Vorpommern, NE Germany) from the legacy of Franz Fukarek. Archiv für Naturschutz und Landschaftsforschung 44(3): 93-108.
De Klerk, P. & Donner, N.: Paläoökologische Untersuchungen zur Entwicklung von Polygonmooren in NO Jakutien. Palynol-Bulletin 1(3/4): 9.
2004:
De Klerk, P.: Confusing concepts in Lateglacial stratigraphy and geochronology: origin, consequences, conlusions (with special emphasis on the type locality Bøllingsø). Review of Palaeobotany and Palynology 129: 265-298.
De Klerk, P.: The pollen diagram “Repten CRep 89/2” (Niederlausitz, S Brandenburg, E Germany) from the legacy of Klaus Kloss. Archiv für Naturschutz und Landschaftsforschung 43(4): 9-17.
De Klerk, P.: A pollen diagram from a kettle-hole mire near the Kalksee (N Brandenburg, NE Germany) from the legacy of Klaus Kloss. Archiv für Naturschutz und Landschaftsforschung 43(4): 19-28.
De Klerk, P.: Changes in vegetation and environment at the Lateglacial-Holocene transition in Vorpommern (Northeast Germany). Internationale Archäologie – Arbeitsgemeinschaft, Tagung, Symposium, Kongress 5: 27-42.
De Klerk, P.: Vegetation history and landscape development of the “Friedländer Große Wiese” region (Vorpommern, NE Germany) inferred from four pollen diagrams of Franz Fukarek. Eiszeitalter und Gegenwart 54: 71-94.
Terberger, T., de Klerk, P., Helbig, H., Kaiser, K. & Kühn, P.: Late Weichselian landscape development and human settlement in Mecklenburg-Vorpommern (NE Germany). Eiszeitalter und Gegenwart 54: 138-175.
2003:
De Klerk, P.: Additional AMS 14C-dates from the Reinberg basin (Vorpommern, NE Germany): Supplemental report to DFG project Bi 560/1-5 “Präzisierung der frühesten Vegetationsentwicklung anhand der Lokalität Reinberg”. Project Report, Geographical Institute, Ernst-Moritz-Arndt-University Greifswald, 5 pp.
2002:
De Klerk, P.: Changing vegetation patterns in the Endinger Bruch area (Vorpommern, NE Germany) during the Weichselian Lateglacial and Early Holocene. Review of Palaeobotany and Palynology 119: 275-309.
De Klerk, P. & Stolze, S.: Unterschiede in Vegetation und Sedimentation zwischen N-Vorpommern und S-Mecklenburg: ein spätglazialer Klimagradient? Greifswalder Geographische Arbeiten 26: 161-165.
Helbig, H. & de Klerk, P.: Geoökologische Prozesse des Pleni- und Spätglazials in der Hohlform “Reinberg”, Nordvorpommern. Greifswalder Geographische Arbeiten 26: 31-34.
Helbig, H. & de Klerk, P.: Befunde zur spätglazialen fluvial-limnischen Morphodynamik in kleinen Talungen Vorpommerns. Eiszeitalter und Gegenwart 51: 51-66.
Helbig, H., de Klerk, P., Kühn, P. & Kwasniowski, J.: Colluvial sequences on till plains in Vorpommern (NE Germany). Zeitschrift für Geomorphologie N.F., Supplementbände 128: 81-100.
Joosten, H. & de Klerk, P.: What’s in a name? Some thoughts on pollen classification, identification, and nomenclature in Quaternary palynology. Review of Palaeobotany and Palynology 122: 29-45.
2001:
Couwenberg, J., de Klerk, P., Endtmann, E., Joosten, H. & Michaelis, D.: Hydrogenetische Moortypen in der Zeit – eine Zusammenschau. In: Succow, M. & Joosten, H. (eds.): Landschaftökologische Moorkunde. E. Schweizerbart’sche Verlagsbuchhandlung (Nägele u. Obermiller), Stuttgart: 399-403.
De Klerk, P.: Vegetation history and palaeoenvironmental development of the Endinger Bruch area and the Reinberg basin (Vorpommern, NE Germany) during the Late Pleniglacial, Lateglacial and Early Holocene (with special emphasis on a widespread stratigraphic confusion). PhD-thesis, Geographical Institute, Ernst-Moritz-Arndt-University Greifswald, 103 pp. + appendices.
De Klerk, P. & Helbig, H.: Präzisierung der frühesten Vegetationsentwicklung anhand der Lokalität Reinberg. Project Report, Geographical Institute, Ernst-Moritz-Arndt-University Greifswald, 16 pp. + appendices.
De Klerk, P., Helbig, H., Helms, S., Janke, W., Krügel, K., Kühn, P., Michaelis, D. & Stolze, S.: The Reinberg Researches: palaeoecological and geomorphological studies of a kettle hole in Vorpommern (NE Germany), with special emphasis on a local vegetation during the Weichselian Pleniglacial/Lateglacial transition. Greifswalder Geographische Arbeiten 23: 43-131.
De Klerk, P., Michaelis, D. & Spangenberg, A.: Auszüge aus der Weichsel-spätglazialen und holozänen Vegetationsgeschichte des Naturschutzgebietes Eldena (Vorpommern). Greifswalder Geographische Arbeiten 23: 187-208.
2000:
Billwitz, K., Helbig, H., Kaiser, K., de Klerk, P., Kühn, P. & Terberger, T.: Untersuchungen zur spätpleistozänen bis frühholozänen Landschafts- und Besiedlungsgeschichte in Mecklenburg-Vorpommern. Neubrandenburger Geologische Beiträge 1: 24-38.
1999:
Kaiser, K., de Klerk, P. & Terberger, T.: Die “Riesenhirschfundstelle” von Endingen: geowissenschaftliche und archäologische Untersuchungen an einem spätglazialen Fundplatz in Vorpommern. Eiszeitalter und Gegenwart 49: 102-123.
1998:
Billwitz, K., Helbig, H., Kaiser, K., de Klerk, P. & Terberger, T.: Chronostratigraphie, geoökologische Entwicklung und menschliche Besiedlung vom Spätglazial zum Holozän in Nordostdeutschland. Project Report, Geographical Institute, Ernst-Moritz-Arndt-University Greifswald, 31 pp. + appendices.
De Klerk, P.: Late Glacial and Early Holocene vegetation history in northern Vorpommern: a preliminary review of available pollen diagrams. Project report, Geographical Institute, Ernst-Moritz-Arndt-University, 34 pp. + appendices.
1997:
De Klerk, P., Janssen, C.R., Joosten, J.H.J. & Törnqvist, T.E.: Species composition of an alluvial hardwood forest in the Dutch fluvial area under natural conditions (2700 cal year BP). Acta Botanica Neerlandica 46: 131-146.
De Klerk, P., Janssen, C.R. & Joosten, J.H.J.: Patterns and processes in natural wetland vegetation in the Dutch fluvial area: a palaeoecological study. Acta Botanica Neerlandica 46: 147-159.
1996:
Wagner, F., Below, R., de Klerk, P., Dilcher, D.L., Joosten, H., Kürschner, W.M. & Visscher, H.: A natural experiment on plant acclimation: lifetime stomatal frequency response of an individual tree to annual atmospheric CO2 increase. Proceedings of the National Academy of Science USA 93: 11705-11708.
1995:
De Klerk, P.: Crevassesystemen van fossiele anastomoserende riviersystemen in de Alblasserwaard. MSc-thesis, Department of Geography, Utrecht University, 28 pp. + appendices.
De Klerk, P.: 3000 years before Ooievaar: vegetation patterns and dynamics in the Dutch fluvial area near Leerdam. Acta Botanica Neerlandica 44: 299-300.
Wagner, F., de Klerk, P. & Joosten, H.: Changes in stomatal parameters of an individual Betula pendula under natural growth conditions. Terra Nostra Schriften der Alfred-Wegener-Stiftung 2(95): 290.
1994:
De Klerk, P.: Mid-subboreal vegetation near the Schaik alluvial ridge (Leerdam, Vijfheerenlanden, Central Netherlands). MSc-thesis, Laboratory of Palaeobotany and Palynology/Department of Geography, Utrecht University, 41 pp + appendices.
1992:
De Klerk, P.: Reconstruction of the natural vegetation at the Schaik alluvial ridge near Leerdam (Central Netherlands) and in the flood basin south of the alluvial ridge – preliminary results. Stuifmail 10: 6-13.