Perhaps you should try some spelling variations:
astronomy surveying » astronomy during
practical astronomy » nautical astronomy, positional astronomy
optical astronomy » nautical astronomy, spherical astronomy, positional astronomy
astronomy surveys » astronomy survey, astronomy survives, astronomy sergey
drops practical » aris practical, devops practices, arrays practical
moore optical » moire optical, more optical, core optical
patrick drops » patrick debois, patrick dr, patrick brown

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 optical astronomy surveying ) OR ( the patrick drops practical astronomy surveys )).
• Adding a wildcard symbol may retrieve word variants: (( the patrick moore optical astronomy surveying ) or ( the patrick drops practical astronomy surveys ))*.