Perhaps you should try some spelling variations:
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 » abcs practical, ics practical, metrics practical
before national » before international
mics practical » ics practical, micro practical, his practical
patrick before » patrick moore, publick before, track before
mackie optical » active optical, face optical, macro 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 before national astronomy sergey ))) OR ( the patrick mackie optical astronomy surveys )).
• Adding a wildcard symbol may retrieve word variants: (((( the patrick ((moocs practical) or (mics practical)) astronomy survey ) or ( the patrick before national astronomy sergey ))) or ( the patrick mackie optical astronomy surveys ))*.