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 seven, astronomy large
moore practical » more practical, moocs practical, mouse practical
gene positional » game positional, gene position, guenon positional
patrick gene » patrick glenn, patrick penel, patrick anne

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 moore practical astronomy sergey ) OR ( the patrick gene positional astronomy surveys ))".
• Adding a wildcard symbol may retrieve word variants: (( the patrick moore practical astronomy sergey ) OR ( the patrick gene positional astronomy surveys ))*.