@book{70010,
	author = {Gruhn, Paul and Cheddie, Harry},
	title = {Safety instrumented systems :},
	publisher = {ISA-The Instrumentation, Systems, and Automation Society,},
	year = {2006},
	address = {Research Triangle Park, NC :},
	edition = {2nd ed.},
	url = {http://www.loc.gov/catdir/toc/ecip0515/2005019336.html}
}