Perhaps you should try some spelling variations:
special effect » special effects, spectral effects, special respect
social exact » social effect, social etats, social et
effect model » effect models, effects model, effects models
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 model ) OR ( social etas model ))) OR ( special effect model )).
• Adding a wildcard symbol may retrieve word variants: (((( social exact model ) or ( social etas model ))) or ( special effect model ))*.