Perhaps you should try some spelling variations:
astronomy sergey » astronomy survey, astronomy surveys, astronomy seven
mouse practical » course practical, rouses practical, use practical
more practical » some practical

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: the patrick ((mouse practical) OR (more practical)) astronomy sergey.
• Adding a wildcard symbol may retrieve word variants: the patrick ((mouse practical) or (more practical)) astronomy sergey*.