@book{42706,
	author = {Hull,, William X. and Sternberg,, Hilgard O'Reilly,},
	title = {Manual de conservacão do solo},
	publisher = {Sec. Agricultura dos E.U.A., Servi—co de Conserva—cão do Solo,},
	year = {imp. 1951},
	series = {Publicacão TC},
	address = {Washington, D.C.}
}