Cita APA

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

Citación estilo Chicago

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

Cita MLA

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