@inbook{1166852391, author={F. Gary Cunningham and Kenneth J. Leveno and Steven L. Bloom and Jodi S. Dashe and Barbara L. Hoffman and Brian M. Casey and Catherine Y. Spong}, title={AnticoncepciĆ³n}, booktitle={Williams Obstetricia, 25e}, publisher={McGraw-Hill Education}, address={New York, NY}, year={2019}, url={accessmedicina.mhmedical.com/content.aspx?aid=1166852391} }