@revista_internacional{619,
  keywords = {Linguistics, uncertainty, decision making, Fuzzy sets, Frequency selective surfaces, Cognition, Grammar, hesitant fuzzy linguistic term sets, Type-2 Fuzzy Sets, Envelope, Comparative linguistic expressions},
  author = {Yaya Liu and Rosa María Rodríguez and H. Hagras and Hongbin Liu and Keyun Qin and Luis Martínez},
  title = {Type-2 fuzzy envelope of hesitant fuzzy linguistic term set: a new representation model of comparative linguistic expression},
  year = {2019},
  journal = {IEEE Transactions on Fuzzy Systems},
  volume = {27},
  pages = {2312-2326},
  issn = {1063-6706},
  url = {https://ieeexplore.ieee.org/document/8637833},
  doi = {10.1109/TFUZZ.2019.2898155},
}