@article{MS2_1976__39_166484,
     author = {David E. Evans},
     title = {On the spectrum of a one-parameter strongly continous representation.},
     journal = {Mathematica Scandinavica},
     pages = {80--82},
     publisher = {mathdoc},
     volume = {39},
     year = {1976},
     zbl = {0356.47023},
     url = {http://geodesic.mathdoc.fr/item/MS2_1976__39_166484/}
}