Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, positional astronomy
national astronomy » national autonomy, nautical astronomy, regional astronomy
optical astronomy » nautical astronomy, spherical astronomy, positional astronomy
astronomy surveys » astronomy surveying, astronomy survives, autonomy survey
astronomy survey » autonomy survey, astronomy surveying, astronomy survives
astronomy sergey » astronomy seven, astronomy large, astronomy society
moocs practical » mics practical, does practical, drops practical
moore national » moors national, more national, before national
mackie optical » active optical, face optical, macro optical
patrick moocs » patrick mons, patrick moyes, patrick moore's

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 moocs practical astronomy survey ) OR ( the patrick moore national astronomy sergey ))) OR ( the patrick mackie optical astronomy surveys )).
• Adding a wildcard symbol may retrieve word variants: (((( the patrick moocs practical astronomy survey ) or ( the patrick moore national astronomy sergey ))) or ( the patrick mackie optical astronomy surveys ))*.