Tanaka; Ino; Murakami
Chemical and Pharmaceutical Bulletin, 1981 , vol. 29, # 7 p. 1876 - 1886

Rebstock et al.
Journal of the American Chemical Society, 1956 , vol. 78, p. 5831

Mavrova, Anelia Ts.; Anichina, Kamelya K.; Vuchev, Dimitar I.; Tsenov, Jordan A.; Kondeva, Magdalena S.; Micheva, Mitka K.
Bioorganic and Medicinal Chemistry, 2005 , vol. 13, # 19 p. 5550 - 5559