@book{13657,
	author = {Wyllie, Duncan C. and Mah, Christopher W.},
	title = {Rock slope engineering :},
	publisher = {Spon Press,},
	year = {2004.},
	address = {London ;},
	edition = {4th ed.},
	note = {"Based on Rock Slope Engineering (third edition, 1981) by  Dr. Evert Hoek and Dr. John Bray."},
	url = {http://www.loc.gov/catdir/toc/ecip046/2003014937.html}
}