1. Chailakhyan, M. Kh., Butenko, R. G., and Lyubarskaya, I. I., Fiziologiya Rastenii, 8, 101 (1961).
2. Salisbury, F. B., and Bonner, J., Plant Physiol., 35, 173 (1960).
3. Bonner, J., and Zeevart, J. A. D., Plant Physiol., 37, 43 (1962).
4. Luzzati, D., C.R. Acad. Sci., Paris, 245, 1466 (1957).
5. Djordjevic, B., and Szybalski, W., J. Exp. Med., 112, 509 (1960).