Prasad, N., A. Sahay, J. Prasad, and K.R.K. Singh. 2010. “Studies on Complexes Arylhydrazones, Part XIII&Mdash;Action of Bromine on 2,3-Dioxo-2-Phenylhydrazono Butyric Acid”. Asian Journal of Chemistry 8 (3):357-60. https://asianpubs.org/index.php/ajchem/article/view/24071.