Perhaps you should try some spelling variations:
"dopnauschwabisches schrifttum heft 1" » "donauschwabisches schrifttum heft 1" (Expand Search), "donauschwabisches christentum heft 1" (Expand Search), "dopnauschwabisches schrifttum heft 3" (Expand Search)
"donauschwabischen schrifttum heft 30" » "donauschwabisches schrifttum heft 30" (Expand Search), "donauschwabisches christentum heft 30" (Expand Search), "donauschwabischen geschichte heft 30" (Expand Search), "donauschwabischen schrifttum heft 3" (Expand Search), "donauschwabischen schrifttum heft 10" (Expand Search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"donauschwabischen schrifttum heft 30\") OR (\"dopnauschwabisches schrifttum heft 1\"))~".
• Removing quotes may allow a broader search: (( donauschwabischen schrifttum heft 30 ) OR ( dopnauschwabisches schrifttum heft 1 ))~.
• Adding a wildcard symbol may retrieve word variants: (("donauschwabischen schrifttum heft 30") OR ("dopnauschwabisches schrifttum heft 1"))*.