To cite icosa in publications use:

Ádám T. Kocsis (2016). Rcpp: Global triangular and hexa-pentagonal grids based on tesselated icosahedra. Journal of I don't know, x(x), x-y. URL http://www.wtf.com

Corresponding BibTeX entry:

  @Article{,
    title = {{icosa}: Global triangular and hexa-pentagonal grids based
      on tesselated icosahedra},
    author = {Ádám T. Kocsis},
    journal = {Journal of I don't know},
    year = {2016},
    volume = {x},
    number = {x},
    pages = {x--y},
    url = {http://www.wtf.com},
  }