@book{31380,
	author = {DAO, Phong Vu and HAO, Yuzon},
	title = {Modern digital and analog communication systems :},
	publisher = {Saunders College Publ.,},
	year = {cop. 1989.},
	address = {Philadelphia [et al.] :},
	url = {http://koha.tu.koszalin.pl/cgi-bin/koha/opac-detail.pl?biblionumber=31380}
}