@book{88186,
	author = {Hernández Martínez, Gildardo.},
	title = {Variabilidad espacial y esquemas de muestreo para nitrógeno},
	publisher = {El autor,},
	year = {2003},
	address = {Chapingo, Méx. :},
	url = {http://10.13.5.2/tesis/99707.pdf}
}