Veber; Milkowski; Varga; Denkewalter; Hirschmann
Journal of the American Chemical Society, 1972 , vol. 94, # 15 p. 5456 - 5461

Pozdnev,V.F. et al.
Chemistry of Natural Compounds, 1979 , vol. 15, p. 471 - 476
Khimiya Prirodnykh Soedinenii, 1979 , vol. 15, p. 543 - 548

Tamamura, Hirokazu; Otaka, Akira; Nakamura, Junko; Okubo, Kaori; Koide, Takaki; Ikeda, Kyoko; Fujii, Nobutaka
Tetrahedron Letters, 1993 , vol. 34, # 31 p. 4931 - 4934