Townsend, Colin R. Essentials of ecology / Colin R. Townsend, Michael Begon, John L. Harper. - 3rd ed. - Malden, MA : Blackwell Publishing, 2008. - xii, 510 p. : col. ill., col. maps ; 25 cm Includes bibliographical references and index ISBN: 9781405156585 (pbk. : alk. paper) RM307.52 Subjects--Topical Terms: Ecology.