@article{villani_miyagi_2004,  title={A hybrid Petri net modeling approach for HVAC systems in intelligent buildings},  volume={15},  ISSN={0103-1759},  url={https://doi.org/10.1590/S0103-17592004000200003},  DOI={10.1590/S0103-17592004000200003},  number={2},  journal={Sba: Controle & Automação Sociedade Brasileira de Automatica},  publisher={Sociedade Brasileira de Automática},  author={Villani, Emilia and Miyagi, Paulo Eigi},  year={2004},  month={Apr},  pages={135–148} }