@book{3849,
	author = {Norton, Mary E. and Scoutt, Leslie M.},
	title = {Callen, ecografía en obstetricia y ginecología},
	publisher = {Elsevier ,},
	year = {2017.},
	address = {Barcelona :},
	edition = {6a ed.},
	note = {Título original: Callen's ultrasonography in obstetrics and gynecology.}
}