1. A. G. Daragan, in: Modern Methods of Producing Shaped Drugs and Galenical Preparations [in Russian], Moscow (1962), p. 69.
2. A. Ya. Drinberg, The Technology of Film-forming Substances [in Russian], Leningrad (1955).
3. British Pharmacopoeia, London (1963), pp. 305, 1157.
4. K. Münzel, Pharm. Acta Helv., No. 2, 38 (1963).
5. V. Coletta and H. Rubin, J. Pharm. Sci.,53, 953 (1964).