Perhaps you should try some spelling variations:
"societal effect model" » "societal effects model", "society effects model", "society affect model", "societal effect models", "societal effects models", "societal effective model"
"social effects model" » "special effects model", "social aspects model", "local effects model", "focal effects model", "social efforts model", "social effects models", "social effect models"
"special effect model" » "special effects model", "spectral effects model", "special event model", "special effect models", "special effects models", "special effective model"
"social effect model" » "local effect model", "focal effect model", "social effort model", "social effect models", "social effects models", "social effective model"
"social exact model" » "social etats model", "social et model", "social email model"

Try widening your search to All Fields.

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 exact model") OR ((((("social effect model") OR ((("societal effect model") OR ("social effects model"))))) OR ("special effect model")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"social exact model\") or (((((\"social effect model\") or (((\"societal effect model\") OR (\"social effects model\"))))) or (\"special effect model\"))))".
• Removing quotes may allow a broader search: (( social exact model ) or ((((( social effect model ) or ((( societal effect model ) OR ( social effects model ))))) or ( special effect model )))).
• Adding a wildcard symbol may retrieve word variants: (("social exact model") or ((((("social effect model") or ((("societal effect model") OR ("social effects model"))))) or ("special effect model"))))*.