Perhaps you should try some spelling variations:
"populism populisms" » "populism populist", "populismus populismus", "populists populists"
"popular populism" » "populists populism", "populism populist", "populist populist"
"popular royalism" » "popular legalism", "popular journalism", "popular radicalism"

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: (((("popular populism") OR ("popular royalism"))) OR ("populism populisms")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"popular populism\") OR (\"popular royalism\"))) or (\"populism populisms\"))".
• Removing quotes may allow a broader search: (((( popular populism ) OR ( popular royalism ))) or ( populism populisms )).
• Adding a wildcard symbol may retrieve word variants: (((("popular populism") OR ("popular royalism"))) or ("populism populisms"))*.