APA (7th ed.) Citation

Seligman, M. E. P. (1998). Learned optimism. Pocket Books.

Chicago Style (17th ed.) Citation

Seligman, Martin E. P. Learned Optimism. New York: Pocket Books, 1998.

MLA (9th ed.) Citation

Seligman, Martin E. P. Learned Optimism. Pocket Books, 1998.