Cita APA (7a ed.)

Trahan, M., & Gray, P. (2011). Focus on psychology: A guide to mastering Peter Gray's Psychology (6th ed.). Worth Publishers.

Cita Chicago Style (17a ed.)

Trahan, Mary, y Peter Gray. Focus on Psychology: A Guide to Mastering Peter Gray's Psychology. 6th ed. New York: Worth Publishers, 2011.

Cita MLA (8a ed.)

Trahan, Mary, y Peter Gray. Focus on Psychology: A Guide to Mastering Peter Gray's Psychology. 6th ed. Worth Publishers, 2011.