1. Mitchell, J. W., and Livingston, G. A., Methods of Studying Plant Hormones and Growth-Regulating Substances, Agriculture Handbook No. 336 (US Government Printing Office, Washington, 1968).
2. Wiemann, J., Thuan, S. T., and Conia, J. M., Bull. Soc. Chim. France, 908 (1957).
3. Organic Synthesis (edit. by Gilman, H., and Blatt, A. H.), 1, 199 (Wiley, New York, 1967).
4. Organic Synthesis (edit. by Gilman, H., and Blatt, A. H.), 1, 345 (Wiley, New York, 1967).