@article{EJDE_2009__2009__a137,
     author = {Wen,  Guo Chun},
     title = {Oblique derivative problems for generalized {Rassias} equations of mixed type with several characteristic boundaries},
     journal = {Electronic journal of differential equations},
     year = {2009},
     volume = {2009},
     zbl = {1171.35440},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2009__2009__a137/}
}