@article{freire_freire_2019,  title={The Ontological Import of Adding Proper Classes},  volume={42},  ISSN={0100-6045},  url={https://doi.org/10.1590/0100-6045.2019.V42N2.RF},  DOI={10.1590/0100-6045.2019.V42N2.RF},  number={2},  journal={Manuscrito},  publisher={UNICAMP - Universidade Estadual de Campinas, Centro de Lógica, Epistemologia e História da Ciência},  author={FREIRE, ALFREDO ROQUE and FREIRE, RODRIGO DE ALVARENGA},  year={2019},  month={Apr},  pages={85–112} }