1. Gramiak R, Shah PM: Echocardiography of the aortic root. Invest Radiol 1968; 3: 356–66.
2. Seward JB, Tajik AJ, Hagler DJ, Ritter DG: Peripheral venous contrast echocardiography. Am J Cardiol 1977; 39: 202–12.
3. Sahn DJ, Allen HD, George W, Mason M, Goldberg SJ: The utility of contrast echocardiographic techniques in the care of critically ill infants with cardiac and pulmonary disease. Circulation 1977; 56: 599–603.
4. Meltzer RS, Roelandt J (eds): Contrast Echocardiography. The Hague: Martinus Nijhoff, 1982.
5. Nanda N: Contrast echocardiography. In: Yu PN, Goodwin JF (eds): Progress in Cardiology. Philadelphia: Lea & Febiger, 1979: 133–45.