@article{MOMA_1978__86_177879,
     author = {Hermann Sohr},
     title = {\"Uber die {Existenz} von {Wellenoperatoren} f\"ur zeitabh\"angige {St\"orungen.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {63--82},
     publisher = {mathdoc},
     volume = {86},
     year = {1978},
     zbl = {0398.34054},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1978__86_177879/}
}