@book {Helly...1992,
	title = {Bruno von Köln: der Vater der Kartäuser},
	year = {1992},
	pages = {149},
	address = {W{\"u}rzburg},
	keywords = {biographiae, Bruno Cartusiensis (biographia)},
	attachments = {http://cartusiana.org./sites/default/files/Helly\%20\%26\%20B\%C3\%B6sen_Bruno\%20von\%20K\%C3\%B6ln_\%20inhoudsopgave.pdf},
	author = {Ange Helly and Willibald B{\"o}sen}
}
