D. E. Butler, P. Bass, I. C. Nordin, F. P. Hauck, Y. J. L'Italien: Novel pharmacological activity of a series of substituted pyridines, in: J. Med. Chem., 1971, 14, S. 575–579; doi:10.1021/jm00289a005
C. R. Smith: Skraup's reaction applied to Phenylenediamines. Preparation of the Phenanthrolines and related Dipyridyls, in: J. Am. Chem. Soc., 1930, 52, S. 397–403; doi:10.1021/ja01364a061