@article{JCA_2015_22_3_JCA_2015_22_3_a1,
     author = {C. Bandle and A. Wagner},
     title = {Isoperimetric {Inequalities} for the {Principal} {Eigenvalue} of a {Membrane} and the {Energy} of {Problems} with {Robin} {Boundary} {Conditions}},
     journal = {Journal of convex analysis},
     pages = {627--64},
     year = {2015},
     volume = {22},
     number = {3},
     url = {http://geodesic.mathdoc.fr/item/JCA_2015_22_3_JCA_2015_22_3_a1/}
}