Perhaps you should try some spelling variations:
practical astronomy » optical astronomy, positional astronomy
blocks practical » clocks practical, books practical, rocks practical
astronomy sergey » astronomy survey, astronomy surveys, astronomy seven
blocks nautical » blocks radical, logs nautical, blocks graphical
patrick blocks » patrick blake, patrick blackett

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 blocks practical astronomy sergey ) OR ( the patrick blocks nautical astronomy sergey ))".
• Adding a wildcard symbol may retrieve word variants: (( the patrick blocks practical astronomy sergey ) OR ( the patrick blocks nautical astronomy sergey ))*.