1. H.T. Tien, S.P. Verma: Nature (London) 227, 1232 (1970)
2. D. S. Berns: Photochem. Photobiol. 24, 117 (1976)
3. M. Calvin: Photochem. Photobiol. 24, 425 (1976)
4. J.J. Katz, J. R. Norris: In Current Topics of Bioeneryetics, Vol. 5, ed. by D.R. Sanadi, L. Packer (Academic Press, New York 1973) p. 41
5. H.T. Witt: In Excited States of Biological Molecules, ed. by J.B. Birks (Wiley-Interscience, London 1976) p. 245