@book{506,
	author = {Rue, Leslie W. and Byars, Lloyd L.},
	title = {Supervision :},
	publisher = {McGraw-Hill Irwin},
	year = {c2001.},
	address = {Boston, Mass. [u.a.]},
	edition = {7th ed.},
	note = {Includes index.},
	url = {http://digitale-objekte.hbz-nrw.de/storage/2006/01/24/file_181/1365325.pdf}
}