K. Ramakrishna Reddy and N. Devanna, and N. Radhakrishna. 2011. “Direct and Derivative Spectrophotometric Determination of Cobalt(II) Using 3,5-Dimethoxy-4- Hydroxybenzaldehydebenzoylhydrazone (DMBBH)”. Journal of International Academy of Physical Sciences 15 (2):249-57. https://www.iaps.org.in/journal/index.php/journaliaps/article/view/605.