@article {37160,
	title = {The limits it common toppling},
	volume = {26},
	year = {1989},
	pages = {737-742},
	publisher = {Canadian Geotechnical Journal },
	url = {http://article.pubs.nrc-cnrc.gc.ca/RPAS/RPViewDoc?_handler_=HandleInitialGet\&calyLang=eng\&journal=cgj\&volume=26\&articleFile=t89-085.pdf},
	author = {Cruden, D. M.}
}
