a systems approach Nayar, K.R. creator text New Delhi APH Publishing Corporation 1998 monographic viii, 210p. 21cm(Hb) by K.R. Nayar Includes bibliographical references and index Ecology Human environment 367.7 NAY 8176480193 A-943837 Cen Lib/Ret DPL 20170124110002.0 EN