@article{MS2_1978__42_166581,
     author = {Herbert Halpern},
     title = {Spectra of operator equations and automorphism groups of von {Neumann} algebras.},
     journal = {Mathematica Scandinavica},
     pages = {135--149},
     publisher = {mathdoc},
     volume = {42},
     year = {1978},
     zbl = {0393.47027},
     url = {http://geodesic.mathdoc.fr/item/MS2_1978__42_166581/}
}