Freeman, Sally; Harger, Martin J.
Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1987 , p. 1399 - 1406

Grabiak, Raymond C.; Miles, James A.; Schwenzer, Gretchen M.
Phosphorus and Sulfur and the Related Elements, 1980 , vol. 9, p. 197 - 202

Hoechst Aktiengesellschaft
Patent: US4632995 A1, 1986 ;