@book{28349,
	author = {Fries, Carl, and Geological Survey (U.S.)},
	title = {Los yacimientos de calcita óptica de la República Mexicana.},
	year = {1948},
	address = {Mexico,},
	note = {Issued in English under title: Optical calcite deposits of the Republic of Mexico (U. S. Geological Survey Bulletin 954-D)}
}