Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy, positional astronomy
astronomy sergey » astronomy survey, astronomy surveys, astronomy seven
moocs practical » mics practical, abcs practical, ics practical
moore practical » mouse practical, course practical, before practical
more practical » some practical
patrick moocs » patrick mons, patrick moyes, patrick moore's
patrick more » patrick moyes, patrick mkie, patrick mark

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