Hinde, Christopher Atanassov, Krassimir T. On intuitionistic fuzzy negations and intuitionistic fuzzy extended modal operators. Part 2. On intuitionistic fuzzy negations and intuitionistic fuzzy extended modal operators. Part 2. untagged;Information and Computing Sciences not elsewhere classified 2009-01-26
    https://repository.lboro.ac.uk/articles/conference_contribution/On_intuitionistic_fuzzy_negations_and_intuitionistic_fuzzy_extended_modal_operators_Part_2_/9404705