Perhaps you should try some spelling variations:
"vieweg studium; grundkurs mathematik" » "vieweg studium; vorkurs mathematik"
"viewed studium; grundkurs mathematik" » "viewed studium; vorkurs mathematik"
"reviewed studies; grundkurs mathematik" » "reviewed studies; vorkurs mathematik", "review studies; grundkurs mathematik", "related studies; grundkurs mathematik", "resolved 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 ("vieweg studium; bruckenkurs mathematik"))) OR ((((("viewed studium; grundkurs mathematik") OR ("viewed studium; grundkurs informatik"))) OR ("reviewed studies; grundkurs 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 (\"viewed studium; grundkurs informatik\"))) or (\"reviewed studies; grundkurs mathematik\"))))".
• Removing quotes may allow a broader search: (((( vieweg studium; grundkurs mathematik ) or ( vieweg studium; bruckenkurs mathematik ))) or ((((( viewed studium; grundkurs mathematik ) OR ( viewed studium; grundkurs informatik ))) or ( reviewed studies; grundkurs mathematik )))).
• Adding a wildcard symbol may retrieve word variants: (((("vieweg studium; grundkurs mathematik") or ("vieweg studium; bruckenkurs mathematik"))) or ((((("viewed studium; grundkurs mathematik") OR ("viewed studium; grundkurs informatik"))) or ("reviewed studies; grundkurs mathematik"))))*.