Wang, L. et al. 2013. Synthesis and Crystal Structure of 4,4’,6,6’-Tetrachloro-2,2’-[(1,4-butylene)dioxybis(nitrilmethylidyne)]diphenol. Asian Journal of Chemistry. 25, 6 (Jan. 2013), 3440–3442. DOI:https://doi.org/10.14233/ajchem.2013.13920A.