Perhaps you should try some spelling variations:
"dopnauschwabisches schrifttum uber. 23" » "donauschwabisches schrifttum uber. 23" (Expand Search), "dopnauschwabisches schrifttums der. 23" (Expand Search)
"donauschwabisches christentum uber. 23" » "donauschwabisches schrifttum uber. 23" (Expand Search), "donauschwabisches christentum der. 23" (Expand Search), "donauschwabisches christentum eine. 23" (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: (("dopnauschwabisches schrifttum uber. 23") OR ("donauschwabisches christentum uber. 23"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"dopnauschwabisches schrifttum uber. 23\") OR (\"donauschwabisches christentum uber. 23\"))".
• Removing quotes may allow a broader search: (( dopnauschwabisches schrifttum uber. 23 ) OR ( donauschwabisches christentum uber. 23 )).
• Adding a wildcard symbol may retrieve word variants: (("dopnauschwabisches schrifttum uber. 23") OR ("donauschwabisches christentum uber. 23"))*.