@book{80977,
	author = {Ali, A B M, Shawkat and Chisty, Khawja, Jakaria Ahmed. Supervisor },
	title = {Design, construction and performance testing of a pc-based digital pabx /},
	publisher = {Department of Computer Science, University of Rajshahi,},
	year = {1997},
	address = {Rajshahi :}
}