Rai, H.C., Annapurna Sharma, Meera Sharma, and Sarita Kumari. 2010. “Synthesis, Spectroscopic and Electrochemical Studies of Cobalt(II) and Nickel(II) Macrocyclic Complexes Derived from Oxalodihydrazide and Aldehydes Propanone”. Asian Journal of Chemistry 22 (3):2267-74. https://asianpubs.org/index.php/ajchem/article/view/11395.