Smart, W. K. (1916). How to write business letters. A.W. Shaw Co..
Chicago Style aipamenaSmart, Walter Kay. How to Write Business Letters. New York : Chicago [etc.]: A.W. Shaw Co., 1916.
MLA aipamenaSmart, Walter Kay. How to Write Business Letters. A.W. Shaw Co., 1916.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.