Perhaps you should try some spelling variations:
"nato science theories 1:, physics" » "nato science three 1:, physics", "national science theories 1:, physics", "nato science theories 3:, physics", "nato science theories 4:, physics", "nato science theories 2:, physics"
"nato science series 1:, physics" » "nato science services 1:, physics", "nato science stories 1:, physics", "nato sciences serious 1:, physics", "national science series 1:, physics", "nato science series 3:, physics", "nato science series 2:, physics"
"nato science theory 1:, physics" » "national science theory 1:, 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 series 1:, physics") OR ((("nato science theories 1:, physics") OR ((("nato science theory 1:, physics") OR ("radio science theory 1:, physics")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"nato science series 1:, physics\") or (((\"nato science theories 1:, physics\") or (((\"nato science theory 1:, physics\") OR (\"radio science theory 1:, physics\"))))))".
• Removing quotes may allow a broader search: (( nato science series 1:, physics ) or ((( nato science theories 1:, physics ) or ((( nato science theory 1:, physics ) OR ( radio science theory 1:, physics )))))).
• Adding a wildcard symbol may retrieve word variants: (("nato science series 1:, physics") or ((("nato science theories 1:, physics") or ((("nato science theory 1:, physics") OR ("radio science theory 1:, physics"))))))*.