Perhaps you should try some spelling variations:
"support der integration theory." » "support der integration through.", "support der information theory.", "support der innovation theory.", "support zur integration theory.", "support sector integration theory.", "support de integration theory.", "support under integration theory.", "support deep integration theory."
"support a integration series." » "support a integration services.", "support a interaction series.", "support a integration server.", "support 3 integration series.", "support 2 integration series.", "support 4 integration series.", "support _ integration series."

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: (("support der integration theory.") OR ("support a integration series."))~.
• Removing quotes may allow a broader search: (( support der integration theory. ) or ( support a integration series. ))~.
• Adding a wildcard symbol may retrieve word variants: (("support der integration theory.") or ("support a integration series."))*.