Παραπομπή APA

Gupta P. K. & Hira D.S. Problems in operations research: Principles and solutions (2003.). S,Chand and company ltd.

Παραπομπή Chicago Style

Gupta P. K. και Hira D.S. Problems in Operations Research: Principles and Solutions. 2003. New Delhi: S,Chand and company ltd.

Παραπομπή MLA

Gupta P. K. και Hira D.S. Problems in Operations Research: Principles and Solutions. 2003. S,Chand and company ltd.