@article{MS2_1977__41_166545,
     author = {Frank Hansen},
     title = {Inner one-parameter groups acting on a factor.},
     journal = {Mathematica Scandinavica},
     pages = {113--116},
     publisher = {mathdoc},
     volume = {41},
     year = {1977},
     zbl = {0372.46066},
     url = {http://geodesic.mathdoc.fr/item/MS2_1977__41_166545/}
}