APA (7th ed.) Zitazioa

Helling, P. (1992). The grammar and proofreading course. American Management Association.

Chicago Style (17th ed.) Zitazioa

Helling, Pam. The Grammar and Proofreading Course. [Saranac Lake, N.Y.]: American Management Association, 1992.

MLA (9th ed.) Zitazioa

Helling, Pam. The Grammar and Proofreading Course. American Management Association, 1992.