Craig, Andrew S.; Kataky, Ritu; Matthews, Robert C.; Parker, David; Ferguson, George; et al.
Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999), 1990 , # 9 p. 1523 - 1531

Hancock, Robert D.; Thoem, Vivienne J.
Journal of the American Chemical Society, 1982 , vol. 104, # 1 p. 291 - 292

Rasshofer,W. et al.
Justus Liebigs Annalen der Chemie, 1976 , p. 916 - 923