To cite the geeM package in publications use:

McDaniel LS, Henderson NC, Rathouz PJ (2013). “Fast pure R implementation of GEE: application of the Matrix package.” The R Journal, 5, 181–187. https://journal.r-project.org/archive/2013-1/mcdaniel-henderson-rathouz.pdf.

Corresponding BibTeX entry:

  @Article{,
    author = {Lee S. McDaniel and Nicholas C. Henderson and Paul J.
      Rathouz},
    title = {Fast pure {R} implementation of {GEE}: application of the
      {M}atrix package},
    journal = {The {R} Journal},
    year = {2013},
    volume = {5},
    issue = {1},
    pages = {181--187},
    url =
      {https://journal.r-project.org/archive/2013-1/mcdaniel-henderson-rathouz.pdf},
  }