Zhang, W.-M., Qian, S.-S., & You, Z. (2014). Synthesis, Characterization and Crystal Structures of N,N’-bis(5-Fluoro-2-hydroxybenzylidene)-ethylenediamine and 4,4’-Difluoro-2,2’-[(hydrazine-1,2-diylidene)bis(methanylylidene)]diphenol. Asian Journal of Chemistry, 26(22), 7843–7845. https://doi.org/10.14233/ajchem.2014.17999