To cite fclust in publications use:

M.B. Ferraro and P. Giordani (2015) A toolbox for fuzzy clustering using the R programming language, Fuzzy Sets and Systems, 279, 1-16, http://dx.doi.org/10.1016/j.fss.2015.05.001

Corresponding BibTeX entry:

  @Article{,
    title = {A toolbox for fuzzy clustering using the R programming
      language},
    author = {M.B. Ferraro and P. Giordani},
    journal = {Fuzzy Sets and Systems},
    year = {2015},
    volume = {279},
    pages = {1-16},
    url = {http://dx.doi.org/10.1016/j.fss.2015.05.001},
  }