Perhaps you should try some spelling variations:
aggressive disorders » depressive disorders, recessive disorders, aggressive diseases
treatise aggressive » treating aggressive, hepatis aggressive, rates aggressive
und depressive » und depressiver, und depressiven, und depression

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: (( und depressive disorder ) OR ( treatise aggressive disorders ))*.