@article{SF_1977__15_134264,
     author = {A. Clausing},
     title = {Representations of semigroups and extension of invariant linear functionals.},
     journal = {Semigroup forum},
     pages = {327--342},
     year = {1977},
     volume = {15},
     zbl = {0383.47005},
     url = {http://geodesic.mathdoc.fr/item/SF_1977__15_134264/}
}