@book{104490,
	author = {Yépez Mulia, Enrique and Yépez Martínez, Miztli Y.},
	title = {Mecánica analítica /},
	publisher = {UNAM, Facultad de ciencias,},
	year = {2012.},
	series = {Las prensas de las ciencias},
	address = {México, D.F. :},
	edition = {2 ed.}
}