@article{10_4064_cm_60_61_2_637_647,
     author = {E. Fabes and N. Garofalo and S. Salsa},
     title = {A control on the set where a {Green's} function vanishes},
     journal = {Colloquium Mathematicum},
     pages = {637--647},
     publisher = {mathdoc},
     volume = {60},
     number = {2},
     year = {1990},
     doi = {10.4064/cm-60-61-2-637-647},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-60-61-2-637-647/}
}