Kwon, Byoung, M.; Kim, Suk Choong
Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999), 1983 , p. 761 - 764

Cegan, Alexandr; Vecera, Miroslav
Collection of Czechoslovak Chemical Communications, 1984 , vol. 49, # 6 p. 1521 - 1528