@article{700789,
     title = {Die Fortsetzung stetiger Homomorphismen von $\delta $-Halbgruppen},
     booktitle = {General Topology and its Relations to Modern Analysis and Algebra},
     series = {GDML\_Books},
     publisher = {Academia Publishing House of the Czechoslovak Academy of Sciences},
     address = {Praha},
     year = {1972},
     pages = {401-404},
     mrnumber = {MR0369603},
     zbl = {0312.20038},
     url = {http://dml.mathdoc.fr/item/700789}
}

Skula, L. Die Fortsetzung stetiger Homomorphismen von $\delta $-Halbgruppen, dans General Topology and its Relations to Modern Analysis and Algebra, GDML_Books,  (1972), pp. 401-404. http://gdmltest.u-ga.fr/item/700789/