1. Edmonds PD (1981) Methods of experimental physics, vol 19, Ultrasonic. Academic Press, 111 Fifth Avenue, New York, New York, 10003
2. Richardson EG (1952) Ultrasonic physics. Elsevier Publishing Company, 52 Vanderbilt Avenue, New York 17, N.Y.
3. Crawford AE (1955) Ultrasonic engineering. Butterworths Scientific Publications, London
4. Pisani R, Liboni W (1999) Principi fisici degli ultrasuoni. In: Rabbia C, De Lucchi R, Cirillo R (eds) Ecodoppler vascolare. Edizioni Minerva Medica, Torino
5. Dickinson RJ (1986) Refl ection and scattering. In: Hill CR (ed) Physical principles of medical ultrasonics. Ellis Horwood, Chichester