Perhaps you should try some spelling variations:
experimentierten » experimentieren, experimentierens, experimentiert, experimentiertn, experimentierenn, experimentiern
experimentiertn » experimentieren, experimentiert, experimentierens
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 experimentiertn) OR experimentierte ).
• The words AND, OR and NOT may confuse the search; try adding quotes: "( (experimentierten OR experimentiertn) or experimentierte )".
• Adding a wildcard symbol may retrieve word variants: ( (experimentierten OR experimentiertn) or experimentierte )*.