Perhaps you should try some spelling variations:
"supply system international airports." » "supply system international airport.", "supply system international transport.", "supply system international airshow.", "supply system integration airports.", "supply igem international airports.", "supply term international airports.", "supply systems international airports."
"supply grid conservation efforts." » "supply aid conservation efforts.", "supply good conservation efforts.", "supply grass conservation efforts.", "supply crowd conservation efforts.", "supply great conservation efforts.", "support grid conservation efforts."

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("supply grid conservation efforts.") or ("supply system international airports."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("supply grid conservation efforts.") OR ("supply system international airports.")).
• Removing quotes may allow a broader search: (( supply grid conservation efforts. ) or ( supply system international airports. )).
• Adding a wildcard symbol may retrieve word variants: (("supply grid conservation efforts.") or ("supply system international airports."))*.