1. Biokinetics and biodynamics of human differentiation;Blechsmidt,1978
2. Crelin, E., 1981. Development of the musculoskeletal system. In: Netter, F. (Ed.), Ciba Clinical Symposia, vol. 33, no. 1, Summit, New Jersey, plate 21, p. 31.
3. Human Embryology;FitzGerald,1978
4. The Spinal Engine;Gracovetsky,1998
5. Gray's Anatomy, 38th ed., 1995. Churchill Livingstone, New York, pp. 148, 825, 1357.