Perhaps you should try some spelling variations:
"formal languages and automata theory" » "formal languages and automatic theory"
"formal language and automata theory" » "formal language and automatic theory"

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: (((("formal languages and automata theory") OR ("formal language and automata theory"))) OR ("formal languages and automated theorem"))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"formal languages and automata theory\") OR (\"formal language and automata theory\"))) or (\"formal languages and automated theorem\"))*".
• Removing quotes may allow a broader search: (((( formal languages and automata theory ) OR ( formal language and automata theory ))) or ( formal languages and automated theorem ))*.