Perhaps you should try some spelling variations:
"vieweg studium; grundkurs mathematik" » "vieweg studium; grundkurs informatik"
"viewed studium; grundkurs mathematik" » "viewed studium; grundkurs informatik"
"reviewed studies; grundkurs mathematik" » "reviewed studies; grundkurs informatik", "review studies; grundkurs mathematik", "related studies; grundkurs mathematik", "resolved studies; grundkurs mathematik"
"reviewed studies; vorkurs mathematik" » "review studies; vorkurs mathematik", "related studies; vorkurs mathematik", "resolved studies; vorkurs 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 ("vieweg studium; bruckenkurs mathematik"))) OR ((("viewed studium; grundkurs mathematik") OR ((("reviewed studies; grundkurs mathematik") OR ("reviewed studies; vorkurs mathematik")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"vieweg studium; grundkurs mathematik\") or (\"vieweg studium; bruckenkurs mathematik\"))) or (((\"viewed studium; grundkurs mathematik\") or (((\"reviewed studies; grundkurs mathematik\") OR (\"reviewed studies; vorkurs mathematik\"))))))".
• Removing quotes may allow a broader search: (((( vieweg studium; grundkurs mathematik ) or ( vieweg studium; bruckenkurs mathematik ))) or ((( viewed studium; grundkurs mathematik ) or ((( reviewed studies; grundkurs mathematik ) OR ( reviewed studies; vorkurs mathematik )))))).
• Adding a wildcard symbol may retrieve word variants: (((("vieweg studium; grundkurs mathematik") or ("vieweg studium; bruckenkurs mathematik"))) or ((("viewed studium; grundkurs mathematik") or ((("reviewed studies; grundkurs mathematik") OR ("reviewed studies; vorkurs mathematik"))))))*.