@article{MM2_1977__20_154430,
     author = {Dieter Lutz},
     title = {Gruppen und {Halbgruppen} verallgemeinerter {Skalaroperatoren.}},
     journal = {Manuscripta mathematica},
     pages = {105--118},
     publisher = {mathdoc},
     volume = {20},
     year = {1977},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/MM2_1977__20_154430/}
}