@book{6730,
	author = {Gupta, P. K. and Hira, D. S.},
	title = {Problems in Operation Research },
	publisher = {S Chand & Co Ltd,},
	year = {2010.},
	address = {New Delhi},
	url = {http://www.amazon.com/exec/obidos/ASIN/8121909686/chopaconline-20}
}