Perhaps you should try some spelling variations:
"dopnauschwabisches schrifttum der. 23" » "donauschwabisches christentum der. 23" (Expand Search), "dopnauschwabisches schrifttums der. 23" (Expand Search), "dopnauschwabisches schrifttum heft. 23" (Expand Search), "dopnauschwabisches schrifttum und. 23" (Expand Search)
"donauschwabisches schrifttum uber. 23" » "donauschwabisches schrifttums der. 23" (Expand Search), "donauschwabische schrifttum uber. 23" (Expand Search), "donauschwabischen schrifttum uber. 23" (Expand Search)

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("donauschwabisches schrifttum uber. 23") OR ("dopnauschwabisches schrifttum der. 23"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"donauschwabisches schrifttum uber. 23\") OR (\"dopnauschwabisches schrifttum der. 23\"))".
• Removing quotes may allow a broader search: (( donauschwabisches schrifttum uber. 23 ) OR ( dopnauschwabisches schrifttum der. 23 )).
• Adding a wildcard symbol may retrieve word variants: (("donauschwabisches schrifttum uber. 23") OR ("dopnauschwabisches schrifttum der. 23"))*.