@book{21054,
	author = {Anwar Mohamed Hashkel and Mamdouh Abutaleb , },
	title = {Study of the effect of gas concentration and pressure on the intensity of the produced laser lines / },
	publisher = {Anwar Mohamed Hashkel , },
	year = {1996},
	address = {Cairo : },
	url = {http://172.23.153.220/th.pdf}
}