Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy, positional astronomy
course practical » yourself practical, concise practical, care practical
astronomy sergey » astronomy survey, astronomy surveys, astronomy seven
patrick course » patrick corsi, patrick case, patrick count
patrick more » patrick moore, patrick moyes, patrick mark
patrick mkie » patrick mackie, patrick mein, patrick moore

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 course practical astronomy sergey ) OR ( the ((patrick more) OR (patrick mkie)) practical astronomy sergey )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( the patrick course practical astronomy sergey ) or ( the ((patrick more) OR (patrick mkie)) practical astronomy sergey ))".
• Adding a wildcard symbol may retrieve word variants: (( the patrick course practical astronomy sergey ) or ( the ((patrick more) OR (patrick mkie)) practical astronomy sergey ))*.