Perhaps you should try some spelling variations:
"rail projects air force" » "capital projects air force", "rail projects aims force", "rail projects asia force", "rail projects a force"
"road projects air force" » "road projects aims force", "road projects asia force", "road projects a force"
"_ project lab force" » "_ project land force", "_ project larp force", "_ project led force", "_ project la force", "_ project labor force", "_ project a force"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("rail projects air force") OR ("road projects air force"))) or ("_ project lab force"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("rail projects air force") OR ("road projects air force"))) OR ("_ project lab force"))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"rail projects air force\") OR (\"road projects air force\"))) or (\"_ project lab force\"))*".
• Removing quotes may allow a broader search: (((( rail projects air force ) OR ( road projects air force ))) or ( _ project lab force ))*.