@booklet {,
	title = {The cultural ecology, archaeology, and history of terracing and terrace abandonment in the Colca Valley of southern Peru. Technical report to the National Science Foundation and the National Geographic Society},
	volume = {2},
	year = {1988},
	publisher = {University of Wisconsin},
	address = {Madison, WI},
	author = {Denevan, William M.}
}