APA استشهاد

Sviokla, J. J., & Shapiro, B. P. (1993). Keeping customers (11th ed.). HBR.

استشهاد بنمط شيكاغو

Sviokla, John J., و Benson P. Shapiro. Keeping Customers. 11th ed. HBR, 1993.

MLA استشهاد

Sviokla, John J., و Benson P. Shapiro. Keeping Customers. 11th ed. HBR, 1993.