@book{18772,
	author = {Moreno, Luz Marina  and Echavarria, Nestor },
	title = {Pencil solutions /},
	publisher = {Corporación Unificada Nacional de Educación Superior,},
	year = {2018},
	address = {Bogotá (Colombia) :},
	edition = {                   },
	url = {https://drive.google.com/file/d/1xy6_Vu12CBOrMs1vT6EMs4Xxi15yx8p4/view?usp=sharing}
}