@inbook{1195104632,
author={Joseph P. Mathew and Alina Nicoara and Chakib M. Ayoub and Madhav Swaminathan},
title={Native Valve Areas, Velocities, and Gradients},
booktitle={Clinical Manual and Review of Transesophageal Echocardiography, 3e},
publisher={McGraw-Hill Education},
address={New York, NY},
year={2018},
url={accessanesthesiology.mhmedical.com/content.aspx?aid=1195104632}
}