Perhaps you should try some spelling variations:
national astronomy » national autonomy, nautical astronomy, regional 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 » abcs practical, ics practical, metrics practical
mics practical » ics practical, micro practical, his practical
moore national » moors national, more national, before national
mackie optical » face optical, macro optical, machinery optical
active optical » adaptive optical, passive optical

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) OR (mics practical)) astronomy survey ) OR ( the patrick moore national astronomy sergey ))) OR ( the patrick ((mackie optical) OR (active optical)) astronomy surveys )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( the patrick ((moocs practical) or (mics practical)) astronomy survey ) or ( the patrick moore national astronomy sergey ))) or ( the patrick ((mackie optical) OR (active optical)) astronomy surveys ))".
• Adding a wildcard symbol may retrieve word variants: (((( the patrick ((moocs practical) or (mics practical)) astronomy survey ) or ( the patrick moore national astronomy sergey ))) or ( the patrick ((mackie optical) OR (active optical)) astronomy surveys ))*.