@book{13160,
	author = {Troeger, John W. and Troeger, Edna Beatrice.},
	title = {Nature-study readers,},
	publisher = {D. Appleton and company,},
	year = {1897-1902.},
	address = {New York,},
	note = {Vols. 1-4, series title also at head of t.-p.}
}