Bronitsky, Gordon. 1977. ?An Ecological Model Of Trade: Prehistoric Economic Change In The Northern Rio Grande Region Of New Mexico?. Anthropology. Anthropology. University of Arizona. http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=759276391&sid=29&Fmt=1&clientId=43922&RQT=309&VName=PQD.