@book{109485,
	author = {Torres González, Arturo. and Puerto Rico.},
	title = {Use of surface-geophysical techniques for ground-water exploration in the Canovanas-Rio Grande area, Puerto Rico},
	publisher = {U.S. Dept. of the Interior, Geological Survey},
	year = {1985.},
	series = {U.S. Geological Survey water resources-investigations report},
	address = {San Juan, P.R.}
}