Perhaps you should try some spelling variations:
"supply private international airports." » "supply private international airport.", "supply private international transport.", "supply private international airshow.", "supply private information airports.", "supply china international airports.", "supply first international airports."
"slopes measuring national efforts." » "schools measuring national efforts.", "cities measuring national efforts.", "slopes measuring national export.", "slopes measuring national forest."

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: (("slopes measuring national efforts.") OR ("supply private international airports."))~.
• Removing quotes may allow a broader search: (( slopes measuring national efforts. ) or ( supply private international airports. ))~.
• Adding a wildcard symbol may retrieve word variants: (("slopes measuring national efforts.") or ("supply private international airports."))*.