@article{M2AN_1999__33_3_517_0, author = {Benedetto, Dario and Caglioti, Emanuele and Libero, Roberto}, title = {Non-trapping sets and {Huygens} principle}, journal = {ESAIM: Mod\'elisation math\'ematique et analyse num\'erique}, pages = {517--530}, year = {1999}, publisher = {EDP Sciences}, volume = {33}, number = {3}, mrnumber = {1713236}, zbl = {0935.35167}, language = {en}, url = {https://www.numdam.org/item/M2AN_1999__33_3_517_0/} }