Perhaps you should try some spelling variations:
"donauschwabischen schrifttum heft 1" » "dopnauschwabisches schrifttum heft 1" (Expand Search), "donauschwabisches christentum heft 1" (Expand Search), "donauschwabischen geschichte heft 1" (Expand Search), "donauschwabischen schrifttum heft 3" (Expand Search)
"donauschwabisches schrifttum heft 10" » "donauschwabisches schrifttum heft 12" (Expand Search), "donauschwabisches schrifttum heft 19" (Expand Search), "donauschwabisches schrifttum heft 30" (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: (("donauschwabischen schrifttum heft 1") OR ("donauschwabisches schrifttum heft 10"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"donauschwabischen schrifttum heft 1\") OR (\"donauschwabisches schrifttum heft 10\"))*".
• Removing quotes may allow a broader search: (( donauschwabischen schrifttum heft 1 ) OR ( donauschwabisches schrifttum heft 10 ))*.