1. A. Williams , Chemical Technology Review, No. 18: Furans: Synthesis and Applications, Noyes Data Corp., Park Ridge, N. J., 1973, p. 303
2. B. A. Keay and P. W.Dibble, in Comprehensive Heterocyclic Chemistry II, ed. A. R. Katritzky, C. W. Rees and E. F. V. Sciven, Elsevier, Oxford, 1997, vol. 2, p. 395
3. D. M. X. Donnelly and M. J.Meegan, in Comprehensive Heterocyclic Chemistry II, ed. A. R. Katritzky and C. W. Rees, Pergamon, Oxford, 1984, vol. 4, p. 657
4. Five-membered heteroaromatic rings as intermediates in organic synthesis