1. Ambrosio L., Fusco N., Pallara D.: Functions of bounded variations and Free Discontinuity Problems. Clarendon Press, Oxford (2000)
2. Arendt W., Warma M.: The Laplacian with Robin boundary conditions on arbitrary domains. Potential Anal. 19(4), 341–363 (2003)
3. Bossel M.-H.: Membranes élastiquement liées: extension du théorème de Rayleigh-Faber-Krahn et de l’inégalité de Cheeger. C. R. Acad. Sci. Paris Sr. I Math. 302(1), 47–50 (1986)
4. Braides A.: Approximation of free-discontinuity problems. Lecture Notes in Mathematics, vol. 1694. Springer, Berlin (1998)
5. Bucur D., Daners D., An alternative approach to the Faber–Krahn inequality for Robin problems. Calc. Var. Partial Differential Equations (2008, to appear)