00495nam a2200133Ia 4500 180412s9999||||xx |||||||||||||| ||und|| 126133298 Ahmadu Bello University Library - Zaria Edwards, R. W. Conservation ad Productivity of Natural Waters Edited by R. W. Edwards and D. J.Garrod Academic Press Inc.; London 1972 xv, 318p.; ill, diagrs. pictures & ables Includes bibliographical references and index Garrod, D. J. 2728 2728