@article{MM2_1986__55_155152,
     author = {Alfred Baldes},
     title = {Degenerate {Elliptic} {Operators} {Diagonal} {Systems} and {Variational} {Integrals.}},
     journal = {Manuscripta mathematica},
     pages = {467--486},
     publisher = {mathdoc},
     volume = {55},
     year = {1986},
     zbl = {0616.35039},
     url = {http://geodesic.mathdoc.fr/item/MM2_1986__55_155152/}
}