PIĄTKOWSKI WŁODZIMIERZ 288,526 Ecosociology : on the necessity of integrating social and natural sciences in researching man's natural environment / Włodzimierz Piątkowski. - [Kraków, 1994]. - [4], 81-85 k. ; 30 cm Odb. z. : International Conference : Training of Experts for European Cooperation on Protection of the Environment and Promotion of Su; stainable Development Cracow, 9-12 December, 1993