Perhaps you should try some spelling variations:
"social effects models" » "special effects models", "social aspects models", "social effect models"
"social net model" » "social news model", "social na model", "social needs model", "social net models"
"social set model" » "social seat model", "social asset model", "social self model"

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 net model") OR ("social set model"))) OR ("social effects models")).
• Removing quotes may allow a broader search: (((( social net model ) or ( social set model ))) or ( social effects models )).
• Adding a wildcard symbol may retrieve word variants: (((("social net model") or ("social set model"))) or ("social effects models"))*.