Perhaps you should try some spelling variations:
optical astronomy » nautical astronomy, positional astronomy
astronomy series » astronomy sergey, gastronomy services, astronomy survives
core spherical » case spherical, cfrp spherical, coma spherical
patrick more » patrick moore, patrick moyes, patrick mkie
more optical » moire optical, core optical, more optimal
patrick core » patrick corr, patrick moore, patrick corsi

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 more optical astronomy series ) OR ( the patrick core spherical astronomy series )).
• Adding a wildcard symbol may retrieve word variants: (( the patrick more optical astronomy series ) or ( the patrick core spherical astronomy series ))*.