@article{COCV_2006__12_4_636_0,
     author = {H\'ebrard, Pascal and Humbert, Emmanuel},
     title = {The geometrical quantity in damped wave equations on a square},
     journal = {ESAIM: Control, Optimisation and Calculus of Variations},
     pages = {636--661},
     publisher = {EDP-Sciences},
     volume = {12},
     number = {4},
     year = {2006},
     doi = {10.1051/cocv:2006015},
     mrnumber = {2266812},
     zbl = {1108.35105},
     language = {en},
     url = {http://www.numdam.org/articles/10.1051/cocv:2006015/}
}