Grzegorz Pienkowski 
Department of regional and Petroleum Geology, Polish Geological Institute, Rakowiecka
Pienkowski G. and Niedzwiedzki G., 2005, Pterosaur Tracks from the early Kimmeridgian intertidal deposits of Wierzbica, Poland. Geological Quarterly, 49 (3): pp 339-346. Warszawa.