@article{SF_1991__42_3_135084,
     author = {A. Favini},
     title = {Parabolicity of second order differential equations in {Hubert} space.},
     journal = {Semigroup forum},
     pages = {303--312},
     publisher = {mathdoc},
     volume = {42},
     number = {3},
     year = {1991},
     zbl = {0743.47038},
     url = {http://geodesic.mathdoc.fr/item/SF_1991__42_3_135084/}
}