1. Ya. A. Levin, A. V. Il'yasov, I. D. Morozova, A. Sh. Mukhtarov, and M. S. Skorobogatova, ?Formation of phosphorus-containing nitroxyl radicals by photolysis of 2-methyl-2-nitrosopropane in unsaturated phosphonate esters?, Izv. Akad. Nauk SSSR, Ser. Khim., No. 2, 314 (1975).
2. A. V. Il'yasov, Ya. A. Levin, A. Sh. Mukhtarov, and M. S. Skorobogatova, ?ESR spectra of structure of some phosphorus-containing nitroxyl radicals?, Teor. Eksp. Khim.,11, No. 5, 612 (1975).
3. E. W. Stone and A. H. Maki, ?Hindered internal rotation and ESR spectroscopy?, J. Chem. Phys.,37, No. 6, 1326 (1962).
4. R. W. Fessenden, ?ESR studies of internal rotation in radicals?, J. Chem. Phys., No. 6, 1570 (1964).
5. P. J. Krusic and J. K. Kochi, ?Conformational effects of sulfur, silicon, germanium, and tin on alkyl radicals. An electron spin-resonance study of the barriers to internal rotation?, J. Am. Chem. Soc.,93, No. 4, 846 (1971).