Perhaps you should try some spelling variations:
"vieweg studium; grundkurs mathematik" » "vieweg studium; bruckenkurs mathematik", "vieweg studium; vorkurs mathematik", "vieweg studium; grundkurs informatik"
"viewed studium; grundkurs mathematik" » "viewed studium; bruckenkurs mathematik", "viewed studium; vorkurs mathematik", "viewed studium; grundkurs informatik"
"reviewed studies; Grundkurs Mathematik" » "review studies; Grundkurs Mathematik", "related studies; Grundkurs Mathematik", "repeated studies; Grundkurs Mathematik"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("vieweg studium; grundkurs mathematik") OR ((("viewed studium; grundkurs mathematik") OR ((("reviewed studies; Grundkurs Mathematik") OR ("resolved studies; Grundkurs Mathematik")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"vieweg studium; grundkurs mathematik\") or (((\"viewed studium; grundkurs mathematik\") or (((\"reviewed studies; Grundkurs Mathematik\") OR (\"resolved studies; Grundkurs Mathematik\"))))))".
• Removing quotes may allow a broader search: (( vieweg studium; grundkurs mathematik ) or ((( viewed studium; grundkurs mathematik ) or ((( reviewed studies; Grundkurs Mathematik ) OR ( resolved studies; Grundkurs Mathematik )))))).
• Adding a wildcard symbol may retrieve word variants: (("vieweg studium; grundkurs mathematik") or ((("viewed studium; grundkurs mathematik") or ((("reviewed studies; Grundkurs Mathematik") OR ("resolved studies; Grundkurs Mathematik"))))))*.