@book{87826,
	author = {Nava Sánchez, Rigoberto.},
	title = {Efecto de la mezcla de semen en la fertilidad de ovejas Suffolk},
	publisher = {El autor,},
	year = {2003},
	address = {Chapingo, Méx. :},
	url = {http://10.13.5.2/tesis/99343.pdf}
}