Perhaps you should try some spelling variations:
"dopnauschwabisches schrifttum heft 12" » "donauschwabisches christentum heft 12" (Expand Search), "dopnauschwabisches schrifttum heft 1" (Expand Search), "dopnauschwabisches schrifttum heft 2" (Expand Search), "dopnauschwabisches schrifttum heft 10" (Expand Search)
"donauschwabisches schrifttum heft 9" » "donauschwabisches schrifttum heft 3" (Expand Search), "donauschwabisches schrifttum heft 1" (Expand Search), "donauschwabisches schrifttum heft 2" (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: (("dopnauschwabisches schrifttum heft 12") OR ("donauschwabisches schrifttum heft 9"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"dopnauschwabisches schrifttum heft 12\") OR (\"donauschwabisches schrifttum heft 9\"))".
• Removing quotes may allow a broader search: (( dopnauschwabisches schrifttum heft 12 ) OR ( donauschwabisches schrifttum heft 9 )).
• Adding a wildcard symbol may retrieve word variants: (("dopnauschwabisches schrifttum heft 12") OR ("donauschwabisches schrifttum heft 9"))*.