1. A. N. Nesmeyanov, R. Kh. Freidlina, and N. A. Semenov. Izvest. Akad. Nauk SSSR, Otdel. Khim. Nauk, 993 (1955).
2. P. C. Kooijman and W. M. Wagner, Rec.77, 923 (1958).
3. I. L. Kotlyarevskii and A. I. Korbukh. Works of the East Siberian Branch, Acad. Sci., USSR, Chem. Series, (1956), p. 26.
4. Marui, Sci. Rep. Tohoku Univ.17, 699 (1928).
5. Germ. Pat. 386619; Chem. Zbl. I. 2633 (1924).