1. Limitation of phonocardiographic assessment of ball variance;Delman;Ann. Thorac. Surg.,1970
2. Phonocardiographic diagnosis of aortic ball variance;Hylen;Circulation,1968
3. Phonocardiographic and hemodynamic correlates of simulated aortic ball variance;Delman;Circulation,1969
4. Correspondence on variant ball;Delman;Ann. Thorac. Surg.,1971
5. Sound spectrograms in simulated aortic ball variance;Delman;Circulation,1970