Perhaps you should try some spelling variations:
international computer » international center
root extraction » root restriction, root extract, root extracts
computer root » computer room, computer rooms, computer book
methods linda » methods index, methods clinical
methods line » methods blind, methods links, methods land

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: international computer root extraction ((((methods line) or (methods linda))) or (methods linear))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: international computer root extraction ((((methods line) OR (methods linda))) OR (methods linear)).
• Adding a wildcard symbol may retrieve word variants: international computer root extraction ((((methods line) or (methods linda))) or (methods linear))*.