@book{20913,
	author = {Catholic Church. and Dopf, Hubert. and Wiener Hofburgkapelle.},
	title = {Gregorian chant},
	publisher = {Philips,},
	year = {p1986.},
	series = {Digital classics},
	address = {[S.l.] :},
	note = {Sung in Latin.}
}