1. H. Amann, Multiplication in Sobolev and Besov Spaces. In Nonlinear Analysis. Scuola Norm. Sup. di Pisa Quaderni (1991) 27–50.
2. Boggio T., Sulle funzioni di Green d’ordinem.Rend. Circ. Mat. Palermo20(1905) 97–135.
3. Escher J., Laurençot Ph. and Walker Ch., Finite time singularity in a free boundary problem modeling MEMS.C. R. Acad. Sci. Paris Sér. I Math.351(2013) 807–812.
4. Escher J., Laurençot Ph. and Walker Ch., A parabolic free boundary problem modeling electrostatic MEMS.Arch. Ration. Mech. Anal.211(2014) 389–417.
5. Escher J., Laurençot Ph. and Walker Ch., Dynamics of a free boundary problem with curvature modeling electrostatic MEMS.Trans. Amer. Math. Soc.367(2015) 5693–5719.