To cite 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. http://www.jstatsoft.org/v52/i05/.

Corresponding BibTeX entry:

  @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},
    url = {http://www.jstatsoft.org/v52/i05/},
  }