Earth, air, and water : resources and environment in the late 20th century / I.G. Simmons. Simmons, I. G. (Ian Gordon), 1937- Human ecology. Natural resources. Conservation of natural resources. GF41 .S5 1991 333.7 20 SIE Includes bibliographical references and index. London ; New York : Edward Arnold : Distributed in the USA by Routledge, Chapman and Hall, c1991. c1991. 1991 Text vi, 254 p. : eng