@book{110259,
	author = {Briggs, Reginald Peter and Puerto Rico.},
	title = {Provisional geologic map of Puerto Rico and adjacent islands},
	publisher = {U.S. Geological Survey},
	year = {1964.},
	series = {Miscellaneous geologic investigations},
	address = {Washington, D.C.},
	note = {Inset: Map showing relative accuracy of parts of the geologic map.}
}