Tsuri; Haga; Matsui; Kamata; Kakushi; Uchida
Chemical and Pharmaceutical Bulletin, 1992 , vol. 40, # 1 p. 75 - 84

Troyanskii, E. I.; Lazareva, M. I.; Nikishin, G. I.
Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1986 , vol. 35, p. 1428 - 1434
Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1986 , # 7 p. 1575 - 1582

Helberger,J.H.; Sproviero,J.F.
Justus Liebigs Annalen der Chemie, 1963 , vol. 666, p. 67 - 74

GLAXO GROUP LIMITED
Patent: WO2004/50619 A1, 2004 ;
Location in patent: Page 24 ;
WO 2004/050619 A1