Perhaps you should try some spelling variations:
national astronomy » national autonomy, nautical astronomy, regional astronomy
optical astronomy » nautical astronomy, positional astronomy
astronomy survey » astronomy surveys, autonomy survey, astronomy surveying
astronomy sergey » astronomy surveys, astronomy seven, astronomy large
moocs practical » does practical, drops practical, abcs practical
mics practical » ics practical, micro practical, abcs practical
moore national » moors national, more national, before national

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 astronomy) OR (spherical 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 astronomy) OR (spherical 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 astronomy) OR (spherical astronomy)) surveys ))*.