Perhaps you should try some spelling variations:
"social reproduction" » "sexual reproduction"
"social recognition" » "social cognition", "facial recognition", "signal recognition"
"social revolution" » "social evolution", "social regulation"

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: (((((("social revolution") OR ("social recognition"))) OR ("digital revolution"))) OR ("social reproduction")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"social revolution\") OR (\"social recognition\"))) or (\"digital revolution\"))) or (\"social reproduction\"))".
• Removing quotes may allow a broader search: (((((( social revolution ) OR ( social recognition ))) or ( digital revolution ))) or ( social reproduction )).
• Adding a wildcard symbol may retrieve word variants: (((((("social revolution") OR ("social recognition"))) or ("digital revolution"))) or ("social reproduction"))*.