@book{24185,
	author = {Merrill, George P. and Mathews, Edward Bennett,},
	title = {The building and decorative stones of Maryland,},
	publisher = {Johns Hopkins press,},
	year = {1898.},
	address = {Baltimore,},
	note = {At head of title: Maryland Geological survey.},
	url = {http://hdl.loc.gov/loc.gdc/scd0001.00029623806}
}