Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy, positional astronomy
astronomy surveys » astronomy survey, astronomy surveying, astronomy survives
patrick brown » patrick browne, patrick barron, patrick bond
patrick dr » patrick d, patrick _, patrick a

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 dr) OR (patrick brown)) practical astronomy surveys.
• Adding a wildcard symbol may retrieve word variants: the ((patrick dr) or (patrick brown)) practical astronomy surveys*.