1. Q.E. Thompson, Quart. Rep. Sulfur Chem., 5, 245 (1970).
2. R. Connor in H. Gilman (Editor), “Organic Chemistry”, Vol. I., 2nd Ed. John Wiley & Sons, New York, 1943, pp. 861–866.
3. E. Müller (Editor), “Methoden der Organischen Chemie” (Houben-Weyl), Vol. IX, 4th Ed. Georg Thieme Verlag, Stuttgart, 1955.
4. H. Böhme and A. Wagner ibid., pp. 49–54.
5. A. Schöberl and A. Wagner, ibid., pp. 55–82.