To cite clusrank in publications use:

Jiang Y, Lee MT, He X, Rosner B, Yan J (2020). “Wilcoxon Rank-Based Tests for Clustered Data with R Package clusrank.” Journal of Statistical Software, 96(6), 1–26. doi: 10.18637/jss.v096.i06.

Corresponding BibTeX entry:

  @Article{,
    title = {{W}ilcoxon Rank-Based Tests for Clustered Data with {R}
      Package {clusrank}},
    author = {Yujing Jiang and Mei-Ling Ting Lee and Xin He and Bernard
      Rosner and Jun Yan},
    journal = {Journal of Statistical Software},
    year = {2020},
    volume = {96},
    number = {6},
    pages = {1--26},
    doi = {10.18637/jss.v096.i06},
  }