1. S. N. Rzhevkin, Usp. Fiz. Nauk 30 (1-2), 40 (1946).
2. H. Oberst, in Technical Aspects of Sound, Vol. 2: Ultrasonic Range, Underwater Acoustics, Ed. by E. G. Richardson (Elsevier Publ. Co., Amsterdam, London, New York, Princeton, 1957; Voenizdat, Moscow, 1962).
3. E. Meyer, Appl. Acoust. 3, 169 (1970).
4. Technical Aspects of Sound, Vol. 2: Ultrasonic Range, Underwater Acoustics, Ed. by E. G. Richardson (Elsevier Publ. Co., Amsterdam, London, New York, Princeton, 1957; Voenizdat, Moscow, 1962).
5. Yu. A. Kobelev, Akust. Zh. 33 (3), 507 (1987).