Downie, Ian M.; Heaney, Harry; Kemp, Graham
Tetrahedron, 1988 , vol. 44, # 9 p. 2619 - 2624

Marathe et al.
Journal of the University of Bombay, Science: Physical Sciences, Mathematics, Biological Sciences and Medicine, 1952 , vol. 21/3 A, p. 36,37