APA-ийн эшлэл(7 дахь хэвлэлт)

Trahan, M., & Gray, P. (1991). Focus on psychology: A guide to mastering Peter Gray's psychology. Worth.

Чикаго-гийн эшлэл (17 дахь хэвлэлт)

Trahan, Mary, ба Peter Gray. Focus on Psychology: A Guide to Mastering Peter Gray's Psychology. New York: Worth, 1991.

MLA -ийн эшлэл (9 дэх хэвлэлт)

Trahan, Mary, ба Peter Gray. Focus on Psychology: A Guide to Mastering Peter Gray's Psychology. Worth, 1991.