Avila, Donald L., The helping relationship sourcebook. Edited by Donald L. Avila, Arthur W. Combs [and] William W. Purkey. - Boston : Allyn and Bacon, [1971]. - xii, 412 p. : 22 cm. Includes bibliographies. LCCN: 77155863 Subjects--Topical Terms: Helping behavior.Counseling.Humanistic psychology. LC Class. No.: BF637.C6 / A85 1971 Dewey Class. No.: 158.2