Perhaps you should try some spelling variations:
"praktischer philosophie" » "praktische philosophie", "praktischen philosophie", "politischer philosophie"
"practice philosophical" » "practical philosophical", "partie philosophical", "pragmatics philosophical"
"poetical philosophical" » "political philosophical", "practical philosophical", "critical philosophical"
"optical philosophical" » "political philosophical", "critical philosophical", "ethical philosophical"

Try widening your search to All Fields.

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: (("praktischer philosophie") OR ((("practice philosophical") OR ((("poetical philosophical") OR ("optical philosophical")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"praktischer philosophie\") or (((\"practice philosophical\") or (((\"poetical philosophical\") OR (\"optical philosophical\"))))))".
• Removing quotes may allow a broader search: (( praktischer philosophie ) or ((( practice philosophical ) or ((( poetical philosophical ) OR ( optical philosophical )))))).
• Adding a wildcard symbol may retrieve word variants: (("praktischer philosophie") or ((("practice philosophical") or ((("poetical philosophical") OR ("optical philosophical"))))))*.