1. J. B. Trener, Monatsh. Chem., 21, 1111 (1900).
2. A. N. Nesmeyanov, A. M. Baran, L. Eggert, V. N. Postnov, and V. A. Sazonova, Izv. Akad. Nauk SSSR, Ser. Khim., No. 6, 1402 (1979).
3. H. Strahle, W. Seitz, and H. Justen, Ber. Bunsenges. Phys. Chem., 90, 288 (1976).
4. L. A. Kutulya, V. F. Morina, A. E. Shevchenko, and Yu. N. Surov, Zh. Prikl. Spektrosk, 27, 76 (1977).
5. N. N. Vorozhtsov, Fundamentals of the Synthesis of Intermediates and Dyes [in Russian], Goskhimizdat, Moscow (1955), p. 694.