Perhaps you should try some spelling variations:
"survey road information theory." » "survey global information theory.", "survey _ information theory.", "survey debt information theory.", "survey round information theory.", "survey rounds information theory.", "survey rapid information theory."
"support grid irrigation systems." » "support drip irrigation systems.", "support syria irrigation systems.", "support crop irrigation systems.", "support agri irrigation systems.", "support grant irrigation systems.", "support group irrigation systems.", "support grid irrigation system."

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: (("support grid irrigation systems.") OR ("survey road information theory."))~.
• Removing quotes may allow a broader search: (( support grid irrigation systems. ) or ( survey road information theory. ))~.
• Adding a wildcard symbol may retrieve word variants: (("support grid irrigation systems.") or ("survey road information theory."))*.