Operation Research Notes Pdf Introduction to Operation Research: The British/Europeans refer to “operational research”, the Americans to “operations research” – but both are often shortened to just “OR” (which is the term we will use). Operation research by s chand pdf, operations research pk gupta and ds hira s. Operations Research S Chand PDF Operations Research, by Prem Kumar. Operations Research D S Hira Limited preview - 2008. Problems in Operation Research (Principles & Solution): Principles and Solutions D S Hira Limited preview - 1991.