@article {CG2015,
   author = {Christiansen, Snorre and Gillette, Andrew},
   title = {Constructions of some minimal finite element systems},
   journal = {ESAIM: Mathematical Modelling and Numerical Analysis},
   volume = {50},
   number = {3},
   pages = {833-850},
   url = {http://dx.doi.org/10.1051/m2an/2015089},
   year = {2016},
}