@article{SF_1984__28_134649,
     author = {W. Ruppert},
     title = {On joint continuity in semigroups on compact manifolds with boundary.},
     journal = {Semigroup forum},
     pages = {173--186},
     publisher = {mathdoc},
     volume = {28},
     year = {1984},
     zbl = {0527.22003},
     url = {http://geodesic.mathdoc.fr/item/SF_1984__28_134649/}
}