1. For a compilation of free radicals which have been characterized by spectroscopic techniques see:
2. Landolt-B�rnstein, New Series, Group II, Vol. 9, eds. H. Fischer, K.-H. Hellwege (Springer-Verlag, Berlin, 1977).
3. G. Herzberg, The Spectra and Structures of Simple Free Radicals (Cornell Univ. Press, Ithaca, 1971).
4. Free Radicals, ed. J. K. Kochi (J. Wiley, New York, 1973).
5. Free Radicals in Biology, ed. W. A. Pryor (Academic Press, New York 1976-78).