Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy, positional astronomy
national astronomy » national autonomy, nautical astronomy, regional astronomy
astronomy surveys » astronomy surveying, astronomy survives, astronomy sergey
astronomy survey » astronomy sergey, autonomy survey, astronomy surveying
moore practical » more practical, moocs practical, mouse practical
before national » before international
patrick before » publick before, track before

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