@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/} }