1. H. Beinert, in “Biological Applications of Electron Spin Resonance”, eds., H.M.Swartz, J.R. Bolton and D.C. Borg, Chapter 8, Wiley, New York, (1972).
2. I. Isenberg, Physiol. Rev. 44, 487, (1964).
3. A. Vithayathil, J. Ternberg and B. Commoner, Nature (London) 207, 1246, (1965).
4. J. Rowlands and G Gross, Nature (london) 231, 1256, (1967).
5. H, Swartz, Radiat. Res. 24, 579 (1965).