Perhaps you should try some spelling variations:
"radio science theories 2:, physics" » "radio science theory 2:, physics", "radio science theories 3:, physics", "radio science theories 4:, physics", "radio science theories 1:, physics"
"nato science series 2:, physics" » "nato science services 2:, physics", "nato science stories 2:, physics", "nato sciences serious 2:, physics", "national science series 2:, physics", "nato science series 3:, physics"
"radio science three 2:, physics" » "radio science thin 2:, physics", "radio science third 2:, physics", "radio science three 12:, physics", "radio science three 20:, physics", "radio science three 22:, 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 2:, physics") OR ((("radio science theories 2:, physics") OR ("radio science three 2:, physics")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"nato science series 2:, physics\") or (((\"radio science theories 2:, physics\") OR (\"radio science three 2:, physics\"))))".
• Removing quotes may allow a broader search: (( nato science series 2:, physics ) or ((( radio science theories 2:, physics ) OR ( radio science three 2:, physics )))).
• Adding a wildcard symbol may retrieve word variants: (("nato science series 2:, physics") or ((("radio science theories 2:, physics") OR ("radio science three 2:, physics"))))*.