Comparison of the cardiac output and stroke volume response to upright exercise in children with valvular and subvalvular aortic stenosis.
Cyran SE, James FW, Daniels S, Mays W, Shukla R, Kaplan S. Comparison of the cardiac output and stroke volume response to upright exercise in children with valvular and subvalvular aortic stenosis. J Am Coll Cardiol. 1988 Mar; 11(3):651-8.