@inbook{1193307364, author={Glenn D. Posner and Amanda Y. Black and Griffith Jones and Darine El-Chaâr}, title={}, booktitle={Oxorn-Foote Human Labor & Birth, 7e}, publisher={McGraw-Hill Education}, address={New York, NY}, year={2022}, url={obgyn.mhmedical.com/content.aspx?aid=1193307364} }