Perhaps you should try some spelling variations:
"political terrorism" » "biological terrorism"
"political theorist" » "political theorists", "political theories", "political theory"
"critical theorists" » "critical theorist", "critical theories", "political theorists"

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: (((("political theorist") OR ("political terrorism"))) OR ("critical theorists")).
• Removing quotes may allow a broader search: (((( political theorist ) or ( political terrorism ))) or ( critical theorists )).
• Adding a wildcard symbol may retrieve word variants: (((("political theorist") or ("political terrorism"))) or ("critical theorists"))*.