Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy, positional astronomy
astronomy studies » astronomy study, economy studies, astronomy status
astronomy series » astronomy sergey, gastronomy services, astronomy survives
mouse practical » course practical, rouses practical, more practical
moore practical » more practical, moocs practical, course practical
patrick mouse » patrick mons, patrick cousot, patrick mkie

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