Cita APA (7a ed.)

Sullivan, P. N., & Zhong, G. Y. Q. (1989). TOEFL skills for top scores. Arco.

Cita Chicago Style (17a ed.)

Sullivan, Patricia N., y Grace Yi Qiu Zhong. TOEFL Skills for Top Scores. New York: Arco, 1989.

Cita MLA (9a ed.)

Sullivan, Patricia N., y Grace Yi Qiu Zhong. TOEFL Skills for Top Scores. Arco, 1989.