Perhaps you should try some spelling variations:
"programming language" » "programming languages", "program language"
"proof language" » "prolog language", "program language", "process language"
"gram language" » "from language", "program language", "graph languages"

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: (("programming language") OR ((("gram language") OR ("proof language"))))*.
• Removing quotes may allow a broader search: (( programming language ) or ((( gram language ) or ( proof language ))))*.