@article{ferreira_giordano_giordano_2004,  title={Improving selectivity and productivity of the enzymatic synthesis of ampicillin with immobilized penicillin G acylase},  volume={21},  ISSN={0104-6632},  url={https://doi.org/10.1590/S0104-66322004000400002},  DOI={10.1590/S0104-66322004000400002},  number={4},  journal={Brazilian Journal of Chemical Engineering},  publisher={Brazilian Society of Chemical Engineering},  author={Ferreira, A. L. O. and Giordano, R. L. C. and Giordano, R. C.},  year={2004},  month={Oct},  pages={519–529} }