@book{171734,
	author = {Hollnagel, Erik, and ebrary, Inc.},
	title = {The ETTO principle},
	publisher = {Ashgate,},
	year = {c2009.},
	address = {Farnham, England ;},
	note = {Includes index.},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10303007}
}