@article{hart_2005,  title={Visita a Kelsen},  ISSN={0102-6445},  url={https://doi.org/10.1590/S0102-64452005000100010},  DOI={10.1590/S0102-64452005000100010},  number={64},  journal={Lua Nova: Revista de Cultura e Política},  publisher={CEDEC},  author={Hart, H. L. A.},  year={2005},  month={Jan},  pages={153–177} }