Amgen Inc.
Patent: US2003/225106 A1, 2003 ;
Location in patent: Page 86 ;

Naumenko, I. I.; Mikhaleva, M. A.; Mamaev, V. P.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1981 , vol. 17, # 7 p. 710 - 714
Khimiya Geterotsiklicheskikh Soedinenii, 1981 , # 7 p. 958 - 962