1. Bassett, C. A. L.: Electrical Effects in Bone. Scientific American Vol. 213 (1965) p. 18/25.
2. ?, and R. O. Becker: Generation of Electric Potentials by Bone in Response to Mechanical Stress. Science Vol. 137 (1962) p. 1063/1064.
3. ?, R. J. Pawluk, and R. O. Becker: Effects of Electric Currents on Bone in vivo. Nature Vol. 204 (1964) p. 652/654.
4. Bazhenov, V. A.: Piezoelectric Properties of Wood. New York 1961: Consultant Bureau.
5. Cady, W. G.: Piezoelectricity. 1946. Dover Pub.