Perhaps you should try some spelling variations:
information documents » information documentation, information agents, information requirements
documents data » documents a
theory several » theory general
data decision » a decision
theory level » every level, theory local, theory lewis
entry level » country level

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

• Performing a fuzzy search may retrieve terms with similar spellings: information documents data decision ((((theory level) OR (theory several))) or (entry level))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: information documents data decision ((((theory level) OR (theory several))) OR (entry level)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "information documents data decision ((((theory level) OR (theory several))) or (entry level))".
• Adding a wildcard symbol may retrieve word variants: information documents data decision ((((theory level) OR (theory several))) or (entry level))*.