@article{Ghirardi_1997, title={Kelsen y los Universales}, volume={8}, url={https://revistas.pucp.edu.pe/index.php/iusetveritas/article/view/15722}, number={14}, journal={IUS ET VERITAS}, author={Ghirardi, Olsen A.}, year={1997}, month={nov.}, pages={273-277} }