@article{SF_1989__38_2_134949,
     author = {F. Andreu and J.M. Mazon},
     title = {On the boundary spectrum of dominated {Co-semigroups.}},
     journal = {Semigroup forum},
     pages = {129--140},
     publisher = {mathdoc},
     volume = {38},
     number = {2},
     year = {1989},
     zbl = {0686.47035},
     url = {http://geodesic.mathdoc.fr/item/SF_1989__38_2_134949/}
}