@article{bazeia_2004,  title={Field theory},  volume={34},  ISSN={0103-9733},  url={https://doi.org/10.1590/S0103-97332004000700025},  DOI={10.1590/S0103-97332004000700025},  number={4a},  journal={Brazilian Journal of Physics},  publisher={Sociedade Brasileira de Física},  author={Bazeia, Dionisio},  year={2004},  month={Dec},  pages={1458–1460} }