Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy
astronomy surveying » astronomy during
astronomy sergey » astronomy survey, astronomy surveys, astronomy seven
moore positional » aware positional, pure positional, whole positional
moore practical » more practical, mouse practical, course practical
moocs practical » mics practical, does practical, drops practical
patrick moocs » patrick mons, patrick moyes, patrick moore's

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