Virtanen, Reijo
Acta Chemica Scandinavica, Series B: Organic Chemistry and Biochemistry, 1986 , vol. 40, # 5 p. 313 - 327

Srinivasa Rao; Chandrasekharam; Ila; Junjappa
Tetrahedron Letters, 1992 , vol. 33, # 52 p. 8163 - 8164