Wang, K. et al. 2013. Synthesis of Dicationic Carbazole and 4’-Amino-(3,3’-bipyridine)-4-ol and the Spectral Characteristics of Carbazoles. Asian Journal of Chemistry. 25, 8 (Mar. 2013), 4632–4636. DOI:https://doi.org/10.14233/ajchem.2013.14356.