@article {,
	title = {An initial consideration of obsidian procurement and exchange in prehispanic Ecuador},
	journal = {Latin American Antiquity},
	volume = {5},
	number = {3},
	year = {1994},
	pages = {228-255},
	author = {Richard L. Burger and Asaro, Frank and Michael, Helen V. and Stross, Fred H. and Salazar, Ernesto}
}