Cita APA (7a ed.)

Abbs, B., & Freebairn, I. (1992). Discoveries: Students book 1 (18a. ed.). Longman.

Cita Chicago Style (17a ed.)

Abbs, Brian, y Ingrid Freebairn. Discoveries: Students Book 1. 18a. ed. Londres: Longman, 1992.

Cita MLA (9a ed.)

Abbs, Brian, y Ingrid Freebairn. Discoveries: Students Book 1. 18a. ed. Longman, 1992.