Sharma, Anju, et al. “Magneto, Spectral and Thermal Studies on Co2+, Ni2+, Cu2+, Zn2+, Cd2+, UO22+ and VO2+ Chelates of O-[N-α-Pyridimino) Phenol and O-(N-Α-Pyrrolidimino) Phenol”. Asian Journal of Chemistry, vol. 14, no. 1, Mar. 2010, pp. 437-40, https://asianpubs.org/index.php/ajchem/article/view/22034.