Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy
astronomy sergey » astronomy survey, astronomy surveys, astronomy seven
moore practical » more practical, moocs practical, mouse practical
mkie positional » case positional, game positional, gene positional
patrick mkie » patrick mackie, patrick mein, patrick m

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