@article{COCV_2015__21_1_165_0,
     author = {Auchmuty, G. and Rivas, M.A.},
     title = {Unconstrained {Variational} {Principles} for {Linear} {Elliptic} {Eigenproblems}},
     journal = {ESAIM: Control, Optimisation and Calculus of Variations},
     pages = {165--189},
     publisher = {EDP-Sciences},
     volume = {21},
     number = {1},
     year = {2015},
     doi = {10.1051/cocv/2014021},
     mrnumber = {3348419},
     zbl = {1327.35267},
     language = {en},
     url = {http://archive.numdam.org/articles/10.1051/cocv/2014021/}
}