Synthesis of 3-azaharman and other new azacarbolines of the pyridazino[4,5-b]indole type - El-Kashef, Hussein; Farghaly, Abdelrahman A. H.; Floriani, Stephan; Haider, Norbert (ARKIVOC, 2004)
doi: 10.3998/ark.5550190.0004.e19