@book{21179,
	author = {Villanueva Avalos, Alfredo.},
	title = {Control químico de maleza en sandía (Citrullus vulgaris L.) en Coyuca de Benitez, Guerrero, México},
	publisher = {El autor,},
	year = {1994},
	address = {Chapingo, Méx. :}
}