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