Perhaps you should try some spelling variations:
presentation based » representations based, presentation layer, presentation phase
commercial across » commercial crops, commercial actors, commercial crisis
presentation ease » presentation phase, presentation large, presentation layer
across older » across borders, across gender, across modes
older case » older age, other case, der case

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 older case ((presentation ease) or (presentation based)) studies.~.
• If you are trying to use Boolean operators, they must be ALL CAPS: commercial across older case ((presentation ease) OR (presentation based)) studies..
• Adding a wildcard symbol may retrieve word variants: commercial across older case ((presentation ease) or (presentation based)) studies.*.