Perhaps you should try some spelling variations:
astronomy series » astronomy sergey, gastronomy services, astronomy survives
moore practical » more practical, moocs practical, mouse practical
astronomy some » astronomy space, astronomy south, astronomy solar

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