1. V. N. Belov, V. K. Promonenko, N. V. Rodionova, N. I. Skvortsova: In Synthesis of Natural Compounds, their Analogs and Fragments, Nauka, Moskva-Leningrad 1965.
2. R. Lamartine, R. Perrin, G. Bertholen: C. R. Acad. Sci., C291, 219 (1980).
3. R. Lamartine, G. Bertholen, R. Perrin, M. Perrin, A. Thozet: Mol. Cryst.. Liquid Cryst.,52, 597 (1979).
4. Dutch Patent 113, 115, 1966; R. Zh. Khim., 1967, 18P 441.
5. H. C. Ungnade, A. d. McLaren: J. Organ. Chem.,10, 520 (1945).