Perhaps you should try some spelling variations:
international friction » international aviation, international action, international edition
international roman » international human, international road, international roaming
friction economy » fiction economy, aviation economy, production economy
economy series » economics series
roman economy » human economy, command economy, german economy

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 roman economy series ) OR ( international friction economy series ))~.
• Adding a wildcard symbol may retrieve word variants: (( international roman economy series ) or ( international friction economy series ))*.