Perhaps you should try some spelling variations:
"velocity effects model" » "toxicity effects model", "velocity impacts model", "velocity effects models", "velocity effect models"
"societal effect model" » "societal effects model", "social effects model", "society effects model", "societal effect models", "societal effects models", "societal effective 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.

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