Perhaps you should try some spelling variations:
"social exact model" » "social effect model", "social etats model", "social email model"
"social event model" » "social events model", "special event model", "social en model", "social agent model", "social element model", "social rodent model"
"social et model" » "social en model", "social e model", "social etats model", "social net model", "social set model", "social jet 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 exact model") OR ("social event model"))) OR ("social et model"))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"social exact model\") OR (\"social event model\"))) or (\"social et model\"))*".
• Removing quotes may allow a broader search: (((( social exact model ) OR ( social event model ))) or ( social et model ))*.