Perhaps you should try some spelling variations:
presentan » presente, presentacion, presenten, presentean
presented » presente, presenteed
presentes » presente, presents, presentar, presentees
presentaban » presentaron, presentada, presentacion, presenteban, presenteaban
presentadas » presentada, presentado, presentedas, presenteadas
presenta » presente, presentea
present » presente

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: (presentan OR (((presented OR presentes) OR ((presentaban OR presentadas) OR presenta)) OR present))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(presentan or (((presented or presentes) or ((presentaban OR presentadas) or presenta)) or present))~".
• Adding a wildcard symbol may retrieve word variants: (presentan or (((presented or presentes) or ((presentaban OR presentadas) or presenta)) or present))*.