1. A. A. Bredikhin, Z. A. Bredikhina, A. T. Gubaidullin, and I. A. Litvinov, Zh. Obshch. Khim., 2003, 73, 1357 [Russ. J. Gen. Chem., 2003, 73 (Engl. Transl.)].
2. B. B. Lohray and V. Bhushan, Adv. Heterocycl. Chem., 1997, 68, 89.
3. H.-S. Byun, L. He, and R. Bittman, Tetrahedron, 2000, 56, 7051.
4. W. L. F. Armarego, Stereochemistry of Heterocyclic Compounds. Part II Oxygen; Sulfur; Mixed N, O, and S; and Phosphorus Heterocycles, Wiley, New York-London-Sydney-Toronto, 1977, 319.
5. I. Hargittai, The Structure of Volatile Sulfur Compounds, D. Reidel Publishing Co., Dordrecht, 1985.