1. E.G. Rozantsev, Free Nitroxyl Radicals (Plenum Press, New York, 1970)
2. V.N. Parmon, A.I. Kokorin, G.M. Zhidomirov, Stable Biradicals (Nauka, Moscow, 1980)
3. E.G. Rozantsev, R.I. Zhdanov, Nitroxide Radicals, Synthesis, Chemistry, Applications (Nauka, Moscow, 1987)
4. L.B. Volodarsky (Ed), Imidazoline Nitroxides. Synthesis, Properties, Applications, vol. 1, 2 (CRC Press, Boca Raton, 1988)
5. A. Rassat, Pure Appl. Chem. 62(2), 223 (1990)