1. I. D. Kuntz, J. F. Thomason, and C. M. Oshiro, this volume [9].
2. Spin Labelling Methods in Molecular Biology;Likhtenstein,1974
3. Spin Labeling: Theory and Applications,1976
4. L. J. Berliner, this series, Vol. 49, p. 418.
5. P. C. Jost and O. H. Griffith, this series, Vol. 49, p. 369.