APA Citation

Van De Geer ,J.P. (1957). A psychological study of problem solving. Rotterdam: [s.n].

Chicago Style Citation

Van De Geer ,J.P. A Psychological Study of Problem Solving. Rotterdam: [s.n], 1957.

MLA Citation

Van De Geer ,J.P. A Psychological Study of Problem Solving. Rotterdam: [s.n], 1957.

Warning: These citations may not always be 100% accurate.