@article {32658,
	title = {Progestrone levels in peripheral plasma of Rocky Mountain bighorn ewes (Ovis canadensis) during the estrous cycle and pregnancy},
	volume = {58},
	year = {1980},
	pages = {1105-1108},
	publisher = {Canadian Journal of Zoology},
	url = {http://article.pubs.nrc-cnrc.gc.ca/RPAS/RPViewDoc?_handler_=HandleInitialGet\&calyLang=eng\&journal=cjz\&volume=59\&articleFile=z81-094.pdf},
	author = {Whitehead, P. E. and McEwan, E. H.}
}
