Whiting, P. H. (1957). 5 great rules of selling (rev ed.). McGraw-Hill.
Chicago Style aipamenaWhiting, Percy H. 5 Great Rules of Selling. rev ed. New York: McGraw-Hill, 1957.
MLA aipamenaWhiting, Percy H. 5 Great Rules of Selling. rev ed. McGraw-Hill, 1957.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.