1. N. S. Vul'fson, V. G. Zaikin, and A. I. Mikaya, Mass Spectrometry of Organic Compounds [in Russian], Moscow (1986), pp. 128–130, 136, 199–206.
2. N. A. Klyuev, R. A. Khmel'nitskii, I. S. Shpileva, et al., Zh. Nauchn. Prikl, Fotogr. Kinematogr.,20, No. 4, 250–256 (1975).
3. A. A. Polyakova and R. A. Khmel'nitskii, Mass Spectrometry in Organic Chemistry, Leningrad (1972), pp. 113–132.
4. I. V. Romanenko, S. N. Sheinkman, S. N. Baranov, et al., Khim. Geterotsikl. Soedin., No. 12, 1662–1670 (1980).
5. H. Criisten, L. Klasinc, and D. Marsel, Org. Mass. Spectrom.,6, 175–178 (1972).