@Article{jue:14n,
  author =  {T. Takacs and B. J\"uttler and O. Scherzer},
  title =   {Derivatives of Isogeometric Functions on
             $n$-dimensional Rational Patches in $\mathrm{I}\!\mathrm{R}^d$},
  journal = {Computer Aided Geometric Design},
  year =    {2014},
  volume =  {31},
  pages =   {567-581},
  doi =     {10.1016/j.cagd.2014.06.005}
}