@article {, title = {Prehispanic obsidian mines in southern Hidalgo}, journal = {American Antiquity}, volume = {32}, number = {4}, year = {1967}, note = {Source of data: Anthropological Literature, Harvard University}, pages = {542-543}, publisher = {Salt Lake City, 1967}, keywords = {Mexico--Archaeology--Hidalgo, Mexico--Archaeology--Obsidian}, author = {Spence, Michael W.} }