Perhaps you should try some spelling variations:
"national science theories b:, physics" » "natural science theories b:, physics", "spatial science theories b:, physics", "animal science theories b:, physics", "national science theory b:, physics", "national science theories 3:, physics", "national science theories 4:, physics", "national science theories 1:, physics"
"nato science three b:, physics" » "nato science thin b:, physics", "nato science third b:, physics", "radio science three b:, physics", "nato science three big:, physics"
"nato science three 11:, physics" » "nato science thin 11:, physics", "nato science third 11:, physics", "radio science three 11:, physics", "nato science three _:, physics", "nato science three a:, physics"

Try widening your search to All Fields.

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: (("national science theories b:, physics") OR ((("nato science three b:, physics") OR ("nato science three 11:, physics")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"national science theories b:, physics\") or (((\"nato science three b:, physics\") OR (\"nato science three 11:, physics\"))))".
• Removing quotes may allow a broader search: (( national science theories b:, physics ) or ((( nato science three b:, physics ) OR ( nato science three 11:, physics )))).
• Adding a wildcard symbol may retrieve word variants: (("national science theories b:, physics") or ((("nato science three b:, physics") OR ("nato science three 11:, physics"))))*.