Perhaps you should try some spelling variations:
"nato asi substrates f:, computer and system science" » "nato si substrates f:, computer and system science", "nato acid substrates f:, computer and system science", "nato si substrate f:, computer and system science", "nato asi substrates f:, computer and systems science", "nato asi substrates _:, computer and system science", "nato asi substrates a:, computer and system science", "nato asi substrates 8:, computer and system science"
"nato norm subseries f:, computer and system science" » "nato norm subseries f:, computer and systems science", "nato random subseries f:, computer and system science", "nato norm subseries a:, computer and system science", "nato north subseries f:, computer and system science", "nato noch subseries f:, computer and system science"
"nato arw subseries f:, computer and system sciences" » "nato arw subseries f:, computer and systems sciences", "nato _ subseries f:, computer and system sciences", "nato arw subseries a:, computer and system sciences"

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 asi substrates f:, computer and system science") OR ((("nato norm subseries f:, computer and system science") OR ("nato arw subseries f:, computer and system sciences")))).
• Removing quotes may allow a broader search: (( nato asi substrates f:, computer and system science ) or ((( nato norm subseries f:, computer and system science ) or ( nato arw subseries f:, computer and system sciences )))).
• Adding a wildcard symbol may retrieve word variants: (("nato asi substrates f:, computer and system science") or ((("nato norm subseries f:, computer and system science") or ("nato arw subseries f:, computer and system sciences"))))*.