Citazione Stile APA (7a Edizione)

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

Citazione stile Chigago Style (17a edizione)

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

Citatione MLA (9a ed.)

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