Cita APA (7a ed.)

Elsworth, S. (1993). Discoveries: Activity book 1 (18a. ed.). Longman.

Cita Chicago Style (17a ed.)

Elsworth, Steve. Discoveries: Activity Book 1. 18a. ed. Londres: Longman, 1993.

Cita MLA (8a ed.)

Elsworth, Steve. Discoveries: Activity Book 1. 18a. ed. Longman, 1993.