@book{206200,
	author = {Zwick, R. W.},
	title = {Probloompetroleum oil aplications for delaying pear psilla (Homoptera :},
	publisher = { s.n.},
	address = {s.l. :},
	note = {Sobretiro de: The Canadian Entomologist, 110 (3), 1978}
}