1. Organic Sulfur Compounds. Ed. by N. Kharasch, vol. 1 and 2. Oxford: Pergamon 1961, 1966.
2. A. Mustafa, in: Adv. Photochem., ed. by W. A. Noyes Jr., G. S. Hammond and J. N. Pitts Jr., vol. 2, pp. 63–136. New York: Interscience 1964.
3. G. Sosnovsky: Free Radical Reactions in Preparative Organic Chemistry. New York: Macmillan 1964; esp. pp. 62–119.
4. E. E. Gilbert: Sulfonation and related reactions. New York: Interscience 1965.
5. C. F. Reed: USP 2,046,090 of 30. 6. 1936.