Perhaps you should try some spelling variations:
"cover schriftenreihe" » "der schriftenreihe", "eine schriftenreihe", "lernen schriftenreihe"
"zur schriftenreihe" » "der schriftenreihe", "und schriftenreihen", "eine schriftenreihe"
"1.1 schriftenreihe" » "der schriftenreihe", "und schriftenreihen", "eine schriftenreihe"

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("cover schriftenreihe") OR ((("zur schriftenreihe") OR ("1.1 schriftenreihe")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"cover schriftenreihe\") or (((\"zur schriftenreihe\") OR (\"1.1 schriftenreihe\"))))".
• Removing quotes may allow a broader search: (( cover schriftenreihe ) or ((( zur schriftenreihe ) OR ( 1.1 schriftenreihe )))).
• Adding a wildcard symbol may retrieve word variants: (("cover schriftenreihe") or ((("zur schriftenreihe") OR ("1.1 schriftenreihe"))))*.