Perhaps you should try some spelling variations:
"international political economics series" » "international politics economics series", "international political economies series", "international political economits series"
"international political economic theories" » "international politics economic theories", "international political economic theory", "international political economics theory", "international political economic ties"
"international political economy series" » "international politics economy series"

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: (((("international political economics series") OR ("international political economic theories"))) OR ("international political economy series"))~.
• Removing quotes may allow a broader search: (((( international political economics series ) or ( international political economic theories ))) or ( international political economy series ))~.
• Adding a wildcard symbol may retrieve word variants: (((("international political economics series") or ("international political economic theories"))) or ("international political economy series"))*.