Perhaps you should try some spelling variations:
"social network" » "social work"
"social networks" » "social works"
"social works" » "social work's", "social work", "social workers"
"social worka" » "social work", "social worker", "social work's"

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