A source book of Gestalt psychology

MLA

Ellis, Willis D, and Kurt Koffka. A Source Book of Gestalt Psychology. London: Routledge & Kegan Paul, 1938.

APA

Ellis, W. D, & Koffka, K. (1938). A source book of Gestalt psychology. London: Routledge & Kegan Paul.

Chicago

Ellis, Willis D., and Kurt Koffka. A Source Book of Gestalt Psychology. London: Routledge & Kegan Paul, 1938.