Cita APA (7a ed.)

Collier-Macmillan International. (1964). The key to english: Verbs. (1a. ed.). Collier-Macmillan Limited.

Cita Chicago Style (17a ed.)

Collier-Macmillan International. The Key to English: Verbs. 1a. ed. Estados Unidos: Collier-Macmillan Limited, 1964.

Cita MLA (9a ed.)

Collier-Macmillan International. The Key to English: Verbs. 1a. ed. Collier-Macmillan Limited, 1964.