@book{21381,
	author = {Havlin, John L},
	title = {Soil Fertility and Fertilizers: An Introduction to Nutrient Management /},
	publisher = {Prentice Hall,},
	year = {2005.},
	address = {New Jersey :},
	edition = {7.},
	note = {Incluye Bibliografía e Indice Alfabético.}
}