Perhaps you should try some spelling variations:
research contents » research content, research context, research concepts
racing research » tracking research, cracking research, pricing research
online racing » online tracing, online rating, online tracking
line image » linear image, one image

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( line image search document ) OR ( online racing research contents )).
• Adding a wildcard symbol may retrieve word variants: (( line image search document ) or ( online racing research contents ))*.