Perhaps you should try some spelling variations:
based representation » self representation, data representation, la representation
based presentation » case presentation, brief presentation, late presentation
commercial across » commercial crops, commercial actors, commercial crisis
across course » across sources, across more, across our
ease studies » case studies, east studies, based studies

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

• Performing a fuzzy search may retrieve terms with similar spellings: commercial across course ((based presentation) OR (based representation)) ease studies.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "commercial across course ((based presentation) OR (based representation)) ease studies.".
• Adding a wildcard symbol may retrieve word variants: commercial across course ((based presentation) OR (based representation)) ease studies.*.