@book{29213,
	author = {Ruffin, Edmund,},
	title = {An essay on calcareous manures /},
	publisher = {Belknap Press of Harvard University Press, },
	year = {c1961.},
	series = {John Harvard library},
	address = {Cambridge :},
	edition = {3d ed.},
	url = {http://hdl.loc.gov/loc.gdc/scd0001.00027623141}
}