Cita APA (7th ed.)

Liebert, R. M., & Spiegler, M. D. (1990). Personality: Strategies and issues (6th ed.). Brooks/Cole.

Cita Chicago (17th ed.)

Liebert, Robert M., i Michael D. Spiegler. Personality: Strategies and Issues. 6th ed. Pacific Grove, Calif: Brooks/Cole, 1990.

Cita MLA (9th ed.)

Liebert, Robert M., i Michael D. Spiegler. Personality: Strategies and Issues. 6th ed. Brooks/Cole, 1990.