1. C. Reid, Excited States in Chemistry and Biology (Butterworths Scientific Publications Ltd., London, 1957), p. 98.
2. P. Pringsheim, Fluorescence and Phosphorescence (Interscience Publishers, Inc., New York, 1965), p. 333.
3. D. F. Evans, J. Chem. Soc. (a) 1957, 1351, 3885;
4. (b) 1959, 2753.
5. See, for example, the recent review article by K. Gollnick, Advan. Photochem. 5 (1968).ADPCA20065-3152