Perhaps you should try some spelling variations:
"viewed studium; grundkurs mathematik" » "reviewed studies; grundkurs mathematik"
"review studies; vorkurs mathematik" » "review study; vorkurs mathematik"

Try widening your search to All Fields.

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