ACC/AHA Guidelines for the Clinical Application of Echocardiography. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Clinical Application of Echocardiography). Developed in collaboration with the American Society of Echocardiography
Circulation. 1997 Mar 18;95(6):1686-744.
doi: 10.1161/01.cir.95.6.1686.