Cita APA (7th ed.)

Seligman, M. E. (1990). Learned optimism. Pocket bks..

Cita Chicago (17th ed.)

Seligman, Martin E.P. Learned Optimism. New York: Pocket bks., 1990.

Cita MLA (9th ed.)

Seligman, Martin E.P. Learned Optimism. Pocket bks., 1990.