@book{44249,
	author = {Rodríguez-Martínez, Jesús. and Scharlach, Richard A.},
	title = {Geologic and hydrologic data collected at test holes NC-1 and NC-3, Guaynabo and San Juan, eastern Puerto Rico},
	publisher = {Geological Survey},
	year = {1991.},
	series = {Open-file report (U.S. Geological Survey)},
	address = {San Juan, P.R.}
}