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 30" » "donauschwabisches schrifttum heft 3" (Expand Search), "donauschwabisches schrifttum heft 10" (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 30"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"donauschwabischen schrifttum heft 1\") OR (\"donauschwabisches schrifttum heft 30\"))*".
• Removing quotes may allow a broader search: (( donauschwabischen schrifttum heft 1 ) OR ( donauschwabisches schrifttum heft 30 ))*.