Perhaps you should try some spelling variations:
presentation based » representations based, presentation layer, presentation phase
commercial actors » commercial crops, commercial sector, commercial farmers
presentation ease » presentation phase, presentation large, presentation layer
actors one » actors new, actors non, actors roles
one case » some case, one class, one phase

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "commercial actors one case ((presentation ease) OR (presentation based)) studies.~".
• Adding a wildcard symbol may retrieve word variants: commercial actors one case ((presentation ease) OR (presentation based)) studies.*.