@book{181647,
	author = {Webb, Robert H.    and Geological Survey (U.S.)  },
	title = {Lava Falls Rapid in Grand Canyon},
	publisher = {U.S. Dept. of the Interior, U.S. Geological Survey},
	year = {1999. },
	series = {U.S. Geological Survey professional paper},
	address = {Reston, Va.}
}