Perhaps you should try some spelling variations:
"national science service b:, physics" » "natural science service b:, physics", "spatial science service b:, physics", "animal science service b:, physics", "national science service bi:, physics", "national science service bus:, physics", "national science service big:, physics"
"nato science review b:, physics" » "nato evidence review b:, physics", "radio science review b:, physics", "nato science review 1:, physics", "nato science review 15:, physics", "nato science review 14:, physics"
"nato science review 10:, physics" » "nato evidence review 10:, physics", "radio science review 10:, physics", "nato science review 1:, physics", "nato science review 2:, physics", "nato science review 3:, physics"
"nato science service b:, physics" » "radio science service b:, physics", "nato science service bi:, physics", "nato science service bus:, physics", "nato science service big:, 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: (((("nato science review b:, physics") OR ("nato science review 10:, physics"))) OR ((("nato science service b:, physics") OR ("national science service b:, physics")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"nato science review b:, physics\") or (\"nato science review 10:, physics\"))) or (((\"nato science service b:, physics\") OR (\"national science service b:, physics\"))))".
• Removing quotes may allow a broader search: (((( nato science review b:, physics ) or ( nato science review 10:, physics ))) or ((( nato science service b:, physics ) OR ( national science service b:, physics )))).
• Adding a wildcard symbol may retrieve word variants: (((("nato science review b:, physics") or ("nato science review 10:, physics"))) or ((("nato science service b:, physics") OR ("national science service b:, physics"))))*.