@article{JEMS_2014_16_11_a3,
     author = {Jone Apraiz and Luis Escauriaza and Gengsheng Wang and C. Zhang},
     title = {Observability inequalities and measurable sets},
     journal = {Journal of the European Mathematical Society},
     pages = {2433--2475},
     publisher = {mathdoc},
     volume = {16},
     number = {11},
     year = {2014},
     doi = {10.4171/jems/490},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/jems/490/}
}