1. Djerassi, C., Optical Rotatory Dispersion (McGraw-Hill, New York, 1960).
2. Gratzer, W. B., and Cowburn, D. A., Nature, 222, 426 (1969).
3. Doty, P., Holtzer, A. M., Bradbury, J. H., and Blout, E. R., J. Amer. Chem. Soc., 76, 4493 (1954).
4. Applequist, J., and Doty, P., Polyamino Acids, Polypeptides and Proteins (edit. by Stahmann, M. A.) (Univ. of Wisconsin Press, 1962).
5. Jirgensons, B., Natural Organic Macromolecules, 200 (Pergamon, London, 1962).