Wilson, Gertrude. Social group work practice : the creative use of the social process / [by] Gertrude Wilson [and] Gladys Ryland. - Boston, Houghton Mifflin Co. [1949] - xii, 687 p. 23 cm. Bibliography: p. 623-675. Subjects--Topical Terms: Social group work. Dewey Class. No.: 361.8 / WIS