@article{10_4171_ifb_105,
     author = {Marc Droske and Martin Rumpf},
     title = {A level set formulation for {Willmore} flow},
     journal = {Interfaces and free boundaries},
     pages = {361--378},
     year = {2004},
     volume = {6},
     number = {3},
     doi = {10.4171/ifb/105},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ifb/105/}
}