Perhaps you should try some spelling variations:
"social network" » "social networks", "social netyork"
"social worker" » "social world", "social market", "social worlds", "social workser", "social yorker"
"social workers" » "social worlds", "social markets", "social worldss", "social worksers", "social yorkers"
"social work" » "social works", "social york"

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