Perhaps you should try some spelling variations:
"treating aggressive disorders" » "treating depressive disorders", "treating recessive disorders", "treating aggressive diseases", "creating aggressive disorders", "treatise aggressive disorders"
"manisch depressive disorder" » "manic depressive disorder"

Try widening your search to All Fields.

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: (("manisch depressive disorder") OR ("treating aggressive disorders")).
• Removing quotes may allow a broader search: (( manisch depressive disorder ) or ( treating aggressive disorders )).
• Adding a wildcard symbol may retrieve word variants: (("manisch depressive disorder") or ("treating aggressive disorders"))*.