To cite package ‘ZEP’ in publications use:

  Romaniuk M, Parchami A, Grzegorzewski P (2025). _ZEP: Procedures
  Related to the Zadeh's Extension Principle for Fuzzy Data_. R package
  version 0.3.1, <https://github.com/mroman-ibs/zep>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {ZEP: Procedures Related to the Zadeh's Extension Principle for Fuzzy
Data},
    author = {Maciej Romaniuk and Abbas Parchami and Przemyslaw Grzegorzewski},
    year = {2025},
    note = {R package version 0.3.1},
    url = {https://github.com/mroman-ibs/zep},
  }