@article{pasha_narayana_2008,  title={A simple method for the spectrophotometric determination of cephalosporins in pharmaceuticals using variamine blue},  volume={33},  ISSN={0100-4670},  url={https://doi.org/10.1590/S0100-46702008000200006},  DOI={10.1590/S0100-46702008000200006},  number={2},  journal={Eclética Química},  publisher={Fundação Editora da Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP},  author={Pasha, C. and Narayana, B.},  year={2008},  pages={41–46} }