Perhaps you should try some spelling variations:
"greek languages" » "greek language", "tree languages", "graph languages"
"given language" » "driven language", "giving language", "driven languages"
"gen language" » "open language", "when language", "can language"

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: (((("given language") OR ((("greek languages") OR ("free languages"))))) OR ("gen language")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"given language\") or (((\"greek languages\") OR (\"free languages\"))))) or (\"gen language\"))".
• Removing quotes may allow a broader search: (((( given language ) or ((( greek languages ) OR ( free languages ))))) or ( gen language )).
• Adding a wildcard symbol may retrieve word variants: (((("given language") or ((("greek languages") OR ("free languages"))))) or ("gen language"))*.