Perhaps you should try some spelling variations:
plasma literature » plasma literatur, class literature, laser literature
parfa literature » partial literature, sraffa literature, data literature
a filosofia » la filosofia, e filosofia, di filosofia
westen das » testen das, westen der, westfalen das
studium a » studium am, studium ad, studium _
west das » west ak, west a, west d.d

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: ((westen das) OR (west das)) studium a filosofia ((parfa literature) OR (plasma literature)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((westen das) or (west das)) studium a filosofia ((parfa literature) OR (plasma literature))".
• Adding a wildcard symbol may retrieve word variants: ((westen das) or (west das)) studium a filosofia ((parfa literature) OR (plasma literature))*.