Protection of man's natural environment : a collective work / initiated and planned by Władysław Szafer prepared for publication by the editorial committee headed by Włodzimierz Michajłow ; [transl. from the pol. by Andrzej Diniejko et al.]. - Szafer, Władysław (1886-1970); Diniejko, Andrzej (Polish Scientific Publishers, 1973)