1. N. Lindgren, Ultrasonics in medicine, IEEE Spectrum 6, Nov., 48–57 (1969) (this review article is highly recommended to the reader; it covers mostly the present state of ultrasonic imaging, but it also includes a section on early acoustic holography).
2. F. A. Firestone, U.S. patent 2,2,80,226, Apr. 1, 1942.
3. G. Kossoff, D. E. Robinson, and W. J. Garrett, Ultrasonic two-dimensional visualization for medical diagnosis, J. Acoust. Soc. Am. 44, 1310–1318 (1968).
4. Third U.S.-Japan Seminar, Honolulu, 7–13 January, 1973 Appl. Opt. 12, June, 1068 (1973).
5. G. W. Stroke, W. E. Kock, Y. Kikuchi, J. Tsujiuchi, eds., Ultrasonic imaging and holography in medical, sonar and optical applications, Plenum Press, New York, 1974 (a compilation of the 20 papers presented at the 1973 U.S.-Japan Seminar on the subject).