1. Nonuniqueness of equilibrium states for bars in tension,;S. S. Antman;J. Math. Anal. Appl.,1973
2. A gradient bound for entire solutions of quasi-linear equations and its conseguences,;Luis Caffarelli;Comm. Pure Appl. Math.,1994
3. Stima puntuale del gradiente per soluzioni di equazioni ellittiche singolari o degeneri in domini propri con curvatura media nonnegativa,;Diego Castellaneta;avaliable online at {\tt http://www.math.utexas.edu/mp$\_$arc/},2009
4. "Degerate Parabolic Equation,";Emmanuele DiBenedetto;Springer-Verlag,1991
5. The surfaces of Delaunay,;James Eells;Math. Intelligencer,1987