Perhaps you should try some spelling variations:
"nato psi series, series 1: applied sciences" » "nato i series, series 1: applied sciences", "nato ii series, series 1: applied sciences", "nato iii series, series 1: applied sciences", "nato ari series, series 1: applied sciences", "nato psi series, series 2: applied sciences", "nato psi series, series 1: applied science"
"nato psi series, series 3: applied sciences" » "nato i series, series 3: applied sciences", "nato ii series, series 3: applied sciences", "nato iii series, series 3: applied sciences", "nato ari series, series 3: applied sciences", "nato psi series, series 3: applied science"
"nato asi series, series 3: applied sciences" » "nato basic series, series 3: applied sciences", "nato anti series, series 3: applied sciences", "nato capi series, series 3: applied sciences", "nato arw series, series 3: applied sciences", "nato asi series, series 3: applied science"

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 psi series, series 1: applied sciences") OR ((("nato psi series, series 3: applied sciences") OR ("nato asi series, series 3: applied sciences")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"nato psi series, series 1: applied sciences\") or (((\"nato psi series, series 3: applied sciences\") OR (\"nato asi series, series 3: applied sciences\"))))".
• Removing quotes may allow a broader search: (( nato psi series, series 1: applied sciences ) or ((( nato psi series, series 3: applied sciences ) OR ( nato asi series, series 3: applied sciences )))).
• Adding a wildcard symbol may retrieve word variants: (("nato psi series, series 1: applied sciences") or ((("nato psi series, series 3: applied sciences") OR ("nato asi series, series 3: applied sciences"))))*.