@article {FGS2013,
   author = {Floater, Michael and Gillette, Andrew and Sukumar, N.},
   title = {Gradient Bounds for {W}achspress Coordinates on Polytopes},
   journal = {SIAM Journal on Numerical Analysis},
   volume = {52},
   number = {1},
   pages = {515--532},
   url = {http://arxiv.org/abs/1306.4385},
   year = {2014},
}