APA (7th ed.) Zitazioa

Sheldon, L. W. (1920). Twentieth century letter writer (1a. ed.). David Mc Kay, Publisher.

Chicago Style (17th ed.) Zitazioa

Sheldon, L. W. Twentieth Century Letter Writer. 1a. ed. Filadelfia: David Mc Kay, Publisher, 1920.

MLA (9th ed.) Zitazioa

Sheldon, L. W. Twentieth Century Letter Writer. 1a. ed. David Mc Kay, Publisher, 1920.