Perhaps you should try some spelling variations:
"expression directly" » "expression detection", "expressions directly", "expression perfectly", "suppression directly"
"expression direct" » "expressions direct", "expression perfect", "suppression direct"
"expansion der" » "expansion des"

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: (("expansion der") OR ((("expression direct") OR ("expression directly")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"expansion der\") or (((\"expression direct\") OR (\"expression directly\"))))".
• Removing quotes may allow a broader search: (( expansion der ) or ((( expression direct ) OR ( expression directly )))).
• Adding a wildcard symbol may retrieve word variants: (("expansion der") or ((("expression direct") OR ("expression directly"))))*.