@ARTICLE{8993847,
  author={Julián-Iranzo, Pascual and Sáenz-Pérez, Fernando},
  journal={IEEE Transactions on Fuzzy Systems}, 
  title={Proximity-Based Unification An Efficient Implementation Method}, 
  year={2021},
  volume={29},
  number={5},
  pages={1238-1251},
  doi={10.1109TFUZZ.2020.2973129}}