Cita APA (7a ed.)

Thorpe, M., & Grugeon, D. (1987). Open learning for adults. Longman.

Cita Chicago Style (17a ed.)

Thorpe, Mary, y David Grugeon. Open Learning for Adults. [London]: Longman, 1987.

Cita MLA (9a ed.)

Thorpe, Mary, y David Grugeon. Open Learning for Adults. Longman, 1987.