Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy
astronomy sergey » astronomy survey, astronomy surveys, astronomy large
moore practical » more practical, mouse practical, course practical
moocs practical » mics practical, abcs practical, ics practical
astronomy seven » astronomy some, astronomy science, astronomy between
patrick moocs » patrick mons, patrick moyes, patrick moore's
m positional » _ positional, 8 positional, a positional
patrick m » patrick _, patrick a

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