Awadallah, R., El-Haty, M., & Belal, A. (2010). Physico-Chemical Studies on Vanadium(V), Niobium(V) and Tantalum(V) Complexes with Eriochrome cyanine-R and Methylene Blue. Asian Journal of Chemistry, 2(2), 155–167. Retrieved from https://asianpubs.org/index.php/ajchem/article/view/25305