Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy
astronomy surveys » astronomy survey, astronomy surveying, astronomy survives
astronomy sergey » astronomy survey, astronomy large, astronomy society
moore positional » pure positional, whole positional, case positional
aware positional » aware position, swarm positional, aware conditional
moore practical » more practical, moocs practical, mouse practical
astronomy seven » astronomy some, astronomy science, astronomy between
patrick aware » patrick edward, patrick andrew, patrick bajari

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