Perhaps you should try some spelling variations:
investigaciones cientificas » investigacion cientifica (Expand Search), investigaciones juridicas (Expand Search), investigaciones sociologicas (Expand Search)
politicas comparadas » politica comparada (Expand Search), politicos comparados (Expand Search), publicas comparadas (Expand Search)
de investigaciones » de investigacion (Expand Search), e investigacion (Expand Search), la investigacion (Expand Search)
de politicas » de politica (Expand Search), las politicas (Expand Search)
superior de » superior del (Expand Search)
unidad de » comunidad de (Expand Search)