Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy
astronomy sergey » astronomy survey, astronomy surveys, astronomy large
more positional » pure positional, monkey positional, aware positional
astronomy seven » astronomy some, astronomy science, astronomy between
more practical » some practical
patrick more » patrick moore, patrick moyes, patrick mkie

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