To cite multiplex in publications use:

  Rivero Ostoic JA (2020). “Algebraic Analysis of Multiple Social
  Networks with multiplex.” _Journal of Statistical Software_,
  *92*(11), 1-41. doi:10.18637/jss.v092.i11
  <https://doi.org/10.18637/jss.v092.i11>.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Algebraic Analysis of Multiple Social Networks with {multiplex}},
    author = {J. Antonio {Rivero Ostoic}},
    journal = {Journal of Statistical Software},
    year = {2020},
    volume = {92},
    number = {11},
    pages = {1--41},
    doi = {10.18637/jss.v092.i11},
  }