Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy, positional astronomy
astronomy sergey » astronomy survey, astronomy surveys, astronomy seven
patrick moraes » patrick moyes, patrick moore's, patrick morgan

You may be able to get more results by adjusting your search query.

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