Perhaps you should try some spelling variations:
social effect » social effects, societal effect, special effect
social exact » social etats, social et, social email
social etas » social etats, social eclas, social et
etas model » keras model, gas model, das model

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 exact) OR (social effect)) model ) OR ( social etas model )).
• Adding a wildcard symbol may retrieve word variants: (( ((social exact) or (social effect)) model ) or ( social etas model ))*.