1. J. MILLIS and F. B. REED, Biochem. J. 41 (1947) 273.
2. G. LEVY and K. RAO, J. Pharm. Sci. 61 (1972) 279.
3. M. BREMER and T. SCOTT, “Concise Encyclopedia of Biochemistry” (de Gryrter, Berlin, 1983) p. 17.
4. H .F. MARK, N. G. GAYLORD and N. M. BIKALES, “Encyclopedia of Polymer Science and Technology” (Wiley, New York, 1969) Vol. 11, p. 409.
5. H .F. MARK, N. M. BIKALES, C. G. OVERBERGER, G. MENGES and J. T. KROSWIT, “Encyclopedia of Polymer Science and Engineering” (Wiley, New York, 1988) Vol. 13, p. 121.