@book{112062,
	title = {640 - Certificado al proveedor},
	publisher = {Legis Editores S.A.},
	url = {https://login.zproxy.cun.edu.co/login?url=https://www.legiscomex.com/BancoMedios/Documentos%20PDF/certificado-proveedor-640-2013.pdf}
}