APA aipamena

Heinritz, S. F., & Farrell, P. V. (1982). Purchasing: Principles and applications (Sixth edition.). National Book Store.

Chicago Style aipamena

Heinritz, Stuart F., and Paul V. Farrell. Purchasing: Principles and Applications. Sixth edition. Manila: National Book Store, 1982.

MLA aipamena

Heinritz, Stuart F., and Paul V. Farrell. Purchasing: Principles and Applications. Sixth edition. National Book Store, 1982.