McKay, William R.; Proctor, George R.
Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1981 , p. 2435 - 2442
Essawy, A.; El-Hashash, M. A.; El-Gendy, A. M.; Hamad, M. M. M.
Indian Journal of Chemistry, Section B: Organic Chemistry Including Medicinal Chemistry, 1982 , vol. 21, # 6 p. 593 - 595