Perhaps you should try some spelling variations:
"social etats model" » "social ethics model", "social etas model", "social rats model", "social beats model", "social enats model", "social eats model"
"social jet model" » "social je model", "social act model", "social jetlag model", "social net model", "social set model", "social jnet model", "social jset model", "social jet modele"
"social et model" » "social en model", "social e model", "social net model", "social set model", "social et modele"

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