@book{60,
	author = {Symonds, E. M.},
	title = {Obstetricia y ginecología /},
	publisher = {Churchill Livingstone;},
	year = {1993.},
	address = {Madrid: },
	edition = {2a ed.},
	note = {Symonds, E. M. (1993). Obstetricia y ginecología. (2a ed.). Madrid : Churchill Livingstone.}
}