To cite RcppArmadillo in publications use:

Eddelbuettel D, Sanderson C (2014). “RcppArmadillo: Accelerating R with high-performance C++ linear algebra.” Computational Statistics and Data Analysis, 71, 1054–1063. http://dx.doi.org/10.1016/j.csda.2013.02.005.

Corresponding BibTeX entry:

  @Article{,
    title = {RcppArmadillo: Accelerating R with high-performance C++
      linear algebra},
    author = {Dirk Eddelbuettel and Conrad Sanderson},
    journal = {Computational Statistics and Data Analysis},
    year = {2014},
    volume = {71},
    month = {March},
    pages = {1054--1063},
    url = {http://dx.doi.org/10.1016/j.csda.2013.02.005},
  }