@article{MAN_1976__224_162906,
     author = {Harold Donnelly},
     title = {Spectrum and the {Fixed} {Point} {Sets} of {Isometries.}  {I.}},
     journal = {Mathematische Annalen},
     pages = {161--170},
     publisher = {mathdoc},
     volume = {224},
     year = {1976},
     zbl = {0319.53031},
     url = {http://geodesic.mathdoc.fr/item/MAN_1976__224_162906/}
}