Gupta, P. K. (1991). Problems in operations research: Principles and solutions. S. chand & company.
Chicago Style aipamenaGupta, Prem Kumar. Problems in Operations Research: Principles and Solutions. New delhi: S. chand & company, 1991.
MLA aipamenaGupta, Prem Kumar. Problems in Operations Research: Principles and Solutions. S. chand & company, 1991.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.