Unver, Huseyin, et al. “Spectroscopic Properties of 4-Halo-2-(4-chlorophenyliminomethyl)phenol and 4-Halo-2-(4-bromophenyliminomethyl)phenol”. Asian Journal of Chemistry, vol. 18, no. 3, July 2012, pp. 1935-42, https://asianpubs.org/index.php/ajchem/article/view/20898.