00438nam a2200145   45000010005000000030003000050050017000080080041000250350018000660350017000840500023001011000021001242450115001452600032002608920UR20220428113846.0061102|||||||||||||||||||||||||||||||| d  a(janium) 8909  a(janium)8909 4aHC110b.E5F76 19731 aPursell, Carroll10aFrom conservation to ecologyb : the development of enviromental concern : problem studies in american history  bThomas Y. Crowell Co.c1973