To cite package ‘RcppEigen’ in publications use:

  Bates D, Eddelbuettel D (2013). “Fast and Elegant Numerical Linear
  Algebra Using the RcppEigen Package.” _Journal of Statistical
  Software_, *52*(5), 1-24. doi:10.18637/jss.v052.i05
  <https://doi.org/10.18637/jss.v052.i05>.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Fast and Elegant Numerical Linear Algebra Using the {RcppEigen} Package},
    author = {Douglas Bates and Dirk Eddelbuettel},
    journal = {Journal of Statistical Software},
    year = {2013},
    volume = {52},
    number = {5},
    pages = {1--24},
    doi = {10.18637/jss.v052.i05},
  }