@ARTICLE{Keutgen_Norbert_Early_2012, author={Keutgen, Norbert and Walaszczyk, Ireneusz and Remin, Zbigniew}, volume={vol. 62}, number={No 4}, journal={Acta Geologica Polonica}, howpublished={online}, year={2012}, publisher={Komitet Nauk Geologicznych PAN}, publisher={Wydział Geologii UW}, title={Early representatives of the belemnite genus Belemnella (Cephalopoda) from the uppermost Campanian–Lower Maastrichtian of the Middle Vistula River section, central Poland}, URL={http://ochroma.man.poznan.pl/Content/81895/PDF/03keutgen.pdf}, doi={10.2478/v10263-012-0029-4}, }