Perhaps you should try some spelling variations:
societal effect » societal effects, social effects, society effects
social effect » social effects, special effect, local effect
social exact » social etats, social email, social era
social et » social en, social e, social etats

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