@article{brodsky_2004,  title={Gauge theories on the light-front},  volume={34},  ISSN={0103-9733},  url={https://doi.org/10.1590/S0103-97332004000200003},  DOI={10.1590/S0103-97332004000200003},  number={1a},  journal={Brazilian Journal of Physics},  publisher={Sociedade Brasileira de Física},  author={Brodsky, Stanley J.},  year={2004},  month={Mar},  pages={157–165} }