Baik, Woonphil; Kim, Dong Ik; Koo, Sangho; Rhee, Jong Uk; Shin, Sung Hee; Kim, Byeong Hyo
Tetrahedron Letters, 1997 , vol. 38, # 5 p. 845 - 848

Gore; Hughes
Australian Journal of Scientific Research, Series A: Physical Sciences, 1951 , vol. 4, p. 185,191