Perhaps you should try some spelling variations:
"german aerospace cluster" » "german aerospace system", "german space cluster", "global aerospace cluster"
"emc aerospace cluster" » "emc aerospace system", "ieee aerospace cluster", "_ aerospace cluster", "1 aerospace cluster"

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"german aerospace cluster\") OR (\"emc aerospace cluster\"))".
• Removing quotes may allow a broader search: (( german aerospace cluster ) OR ( emc aerospace cluster )).
• Adding a wildcard symbol may retrieve word variants: (("german aerospace cluster") OR ("emc aerospace cluster"))*.