Perhaps you should try some spelling variations:
"polnisch academy of sciences" » "polnische academy of sciences" (Expand Search), "polnischer academy of sciences" (Expand Search), "polnisch academia of sciences" (Expand Search), "polnisch academic of sciences" (Expand Search), "polnisch academie of sciences" (Expand Search)
"polnischen academy of sciences" » "polnischeen academy of sciences" (Expand Search), "polnischeren academy of sciences" (Expand Search), "polnischen academia of sciences" (Expand Search), "polnischen academic of sciences" (Expand Search), "polnischen academie of sciences" (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: (("polnisch academy of sciences") OR ("polnischen academy of sciences"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"polnisch academy of sciences\") OR (\"polnischen academy of sciences\"))".
• Removing quotes may allow a broader search: (( polnisch academy of sciences ) OR ( polnischen academy of sciences )).
• Adding a wildcard symbol may retrieve word variants: (("polnisch academy of sciences") OR ("polnischen academy of sciences"))*.