RIES, A. (1991). Harse sense: The key to success is.. McGraw-Hill.
Chicago Style aipamenaRIES, Al. Harse Sense: The Key to Success Is.. New York: McGraw-Hill, 1991.
MLA aipamenaRIES, Al. Harse Sense: The Key to Success Is.. McGraw-Hill, 1991.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.