@article{EJDE_2015__2015__a89,
     author = {Haoua,  Rabah and Medeghri,  Ahmed},
     title = {Robin boundary value problems for elliptic operational differential equations with variable coefficients},
     journal = {Electronic journal of differential equations},
     year = {2015},
     volume = {2015},
     zbl = {1318.34078},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2015__2015__a89/}
}