Perhaps you should try some spelling variations:
ruhr » ruhe (Expand Search), nuhr (Expand Search)
rohr » lohr (Expand Search)
mohr » mehr (Expand Search), lohr (Expand Search), mohn (Expand Search)
lahr » jahr (Expand Search), lahn (Expand Search), lohr (Expand Search)
bahr » baehr (Expand Search), jahr (Expand Search), bahn (Expand Search)
bahre » baehre (Expand Search), jahre (Expand Search), bahne (Expand Search)
leer » heer (Expand Search), meer (Expand Search)
university » universitat (Expand Search)

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

• Performing a fuzzy search may retrieve terms with similar spellings: (ruhr OR ((rohr OR mohr) OR ((lahr OR (bahr OR bahre)) OR (lehr OR leer)))) university bochum~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(ruhr OR ((rohr OR mohr) OR ((lahr OR (bahr OR bahre)) OR (lehr OR leer)))) university bochum".
• Adding a wildcard symbol may retrieve word variants: (ruhr OR ((rohr OR mohr) OR ((lahr OR (bahr OR bahre)) OR (lehr OR leer)))) university bochum*.