Perhaps you should try some spelling variations:
"societal effect model" » "societal effects model", "social effects model", "society affect model", "societal effect models", "societal effects models", "societal effective model"
"society effects model" » "social effects model", "safety effects model", "velocity effects model", "society effects models", "society effect models"
"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 etats 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 jet model"))) OR ((("societal effect model") OR ("society effects model")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"social et model\") OR (\"social jet model\"))) or (((\"societal effect model\") or (\"society effects model\"))))".
• Removing quotes may allow a broader search: (((( social et model ) OR ( social jet model ))) or ((( societal effect model ) or ( society effects model )))).
• Adding a wildcard symbol may retrieve word variants: (((("social et model") OR ("social jet model"))) or ((("societal effect model") or ("society effects model"))))*.