Perhaps you should try some spelling variations:
competitive improvements » competitive agreements, competitive procurement, competitive enrolment
improvements references » improvement references, movement references, remerciements references
comparative management » compensation management
references history » references list, references factors, references theory
practices history » practice history, prices history, practices historical

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( comparative management practices history ) or ( competitive improvements references history ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( comparative management practices history ) OR ( competitive improvements references history )).
• Adding a wildcard symbol may retrieve word variants: (( comparative management practices history ) or ( competitive improvements references history ))*.