Perhaps you should try some spelling variations:
"experimentierten" » "experimentieren", "experimentiert", "experimentiere", "experimentiertn", "experimentierenn", "experimentiern"
"experimentierenn" » "experimentieren", "experimentierend", "experimentierenden"
"experimentierens" » "experimentieren", "experimentierfeld", "experimenting"
"experimentierte" » "experimentiert", "experimentieren", "experimentier"

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: ((("experimentierten" OR "experimentierenn") OR "experimentierens") OR "experimentierte").
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((\"experimentierten\" OR \"experimentierenn\") or \"experimentierens\") or \"experimentierte\")".
• Removing quotes may allow a broader search: ((( experimentierten OR experimentierenn ) or experimentierens ) or experimentierte ).
• Adding a wildcard symbol may retrieve word variants: ((("experimentierten" OR "experimentierenn") or "experimentierens") or "experimentierte")*.