Perhaps you should try some spelling variations:
"enhancing international airport" » "chairing international airport" (Expand Search), "enhancing interlaminar airport" (Expand Search), "enhancing interpersonal airport" (Expand Search), "enhancing international market" (Expand Search), "enhancing international affairs" (Expand Search)
"changi international airport" » "changi international market" (Expand Search), "changi international affairs" (Expand Search), "jiang international airport" (Expand Search), "chinese international airport" (Expand Search), "hashim international airport" (Expand Search)

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: "((\"enhancing international airport\") OR (\"changi international airport\"))~".
• Removing quotes may allow a broader search: (( enhancing international airport ) OR ( changi international airport ))~.
• Adding a wildcard symbol may retrieve word variants: (("enhancing international airport") OR ("changi international airport"))*.