@article {,
	title = {Classic Maya obsidian trade},
	journal = {American Antiquity},
	volume = {41},
	number = {4},
	year = {1976},
	note = {Source of data: Anthropological Literature, Harvard University},
	pages = {449-464},
	publisher = {Salt Lake City, 1976},
	keywords = {Central America--Archaeology--Obsidian},
	author = {Sidrys, Raymond V.}
}