@book{25491,
	author = {Marshall, R. B.},
	title = {Results of spirit leveling in Maryland, 1896 to 1911, inclusive /},
	publisher = {Govt. Print. Off.,},
	year = {1914.},
	series = {U.S. Geological survey. Bulletin 563},
	address = {Washington,},
	note = {Includes index.}
}