1. R. G. Glushkov, I. B. Levshin, N. B. Marchenko, and E. N. Padeiskaya, Khim.-farm. Zh., No. 9, 1048–1964 (1984).
2. European Patent No. 0078362 (1982).
3. G. N. Dorofeenko, Ortho Esters in Organic Synthesis [in Russian], Rostov-on-Don (1976), pp. 90–95.
4. G. W. H. Cheseman and B. A. Tuck, J. Chem. Soc., 3678 (1965).
5. G. W. H. Cheseman and B. A. Tuck, Chem. Ind., No. 31, 1382 (1965).