“…A number of books and reviews devoted to different aspects of the technique have appeared since 1968.2-19 Several of these are concerned with the synthesis and chemistry of nitroxyls.8,9'13-16,18 Other articles concentrate on biological applications of ESR and spin labeling. 5,6,[10][11][12][13][14]16,17 The reports Electron Spin Resonance annually cover literature on the spin-labeling technique.…”