Perhaps you should try some spelling variations:
"social et model" » "social etats model", "social net model", "social set model", "social jet model"
"social en model" » "social wen model", "social len model", "social pen model"
"social e model" » "social e modelli"

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