Cita APA (7th ed.)

SHELTOR, N., & BURTON, S. (1994). Assertiveness skills. Businnes One Irwin.

Cita Chicago (17th ed.)

SHELTOR, Nelda, i Sharon BURTON. Assertiveness Skills. Burr Ridge: Businnes One Irwin, 1994.

Cita MLA (9th ed.)

SHELTOR, Nelda, i Sharon BURTON. Assertiveness Skills. Businnes One Irwin, 1994.