Perhaps you should try some spelling variations:
"social jetlag model" » "social eulag model", "social lag model", "social tag model", "social jelag model", "social actlag model", "social agentlag model"
"social jet model" » "social je model", "social act model", "social agent 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 ("social jetlag model")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"social et model\") or (((\"social jet model\") OR (\"social jetlag model\"))))".
• Removing quotes may allow a broader search: (( social et model ) or ((( social jet model ) OR ( social jetlag model )))).
• Adding a wildcard symbol may retrieve word variants: (("social et model") or ((("social jet model") OR ("social jetlag model"))))*.