HE, RONG, JUN CHEN, ZHANGJIE HUANG, JIAYUANG YIN, and GUANGYU YANG. 2010. “Determination of Vanadium, Niobium and Tantalum by HPLC Using 2-(2-Quinolinylazo)-Resorcin As Pre-Column Derivatization Reagent”. Asian Journal of Chemistry 19 (5):3851-61. https://asianpubs.org/index.php/ajchem/article/view/13289.