00495nam a2200133Ia 4500008004100000020001400041040004400055100001900099245009200118260003800210300004500248500005000293700001800343180412s9999||||xx |||||||||||||| ||und||  a126133298  aAhmadu Bello University Library - Zaria  aEdwards, R. W. 0aConservation ad Productivity of Natural WaterscEdited by R. W. Edwards and D. J.Garrod  bAcademic Press Inc.; Londonc1972  axv, 318p.; ill, diagrs. pictures & ables  aIncludes bibliographical references and index  aGarrod, D. J.