Perhaps you should try some spelling variations:
"road corporation" » "said corporation"
"railroad corporation" » "railsaid corporation", "railroads corporation"
"_ corporation" » "_ corporate"
"a corporation" » "a corporate"

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: (((((("road corporation") OR ("_ corporation"))) OR ("railroad corporation"))) OR ("a corporation")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"road corporation\") OR (\"_ corporation\"))) or (\"railroad corporation\"))) or (\"a corporation\"))".
• Removing quotes may allow a broader search: (((((( road corporation ) OR ( _ corporation ))) or ( railroad corporation ))) or ( a corporation )).
• Adding a wildcard symbol may retrieve word variants: (((((("road corporation") OR ("_ corporation"))) or ("railroad corporation"))) or ("a corporation"))*.