1. General Electric Research and Development Center, Schenectady, New York 12301
2. Air Force Cambridge Research Laboratory, Bedford, Massachusetts M. W. Friedlander Washington University, St. Louis, Missouri
3. Washington University, St. Louis, Missouri
4. Physics Research Division, Emmanuel College, Lexington, Massachusetts R. S. Rajan, A. S. Tamhane Tata Institute of Fundamental Research, Bombay, India
5. Tata Institute of Fundamental Research, Bombay, India