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