Bernard, H. W. (1977). Principles of Guidance. Harper & Row.
Chicago Style aipamenaBernard, H. W. Principles of Guidance. New York: Harper & Row, 1977.
MLA aipamenaBernard, H. W. Principles of Guidance. Harper & Row, 1977.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.