Perhaps you should try some spelling variations:
optical astronomy » nautical astronomy, spherical astronomy, positional astronomy
astronomy series » gastronomy services, astronomy survives, astronomy studies
astronomy sergey » astronomy survey, astronomy surveys, astronomy large
astronomy seven » astronomy some, astronomy science, astronomy between
patrick moocs » patrick moore, patrick moyes, patrick moore's
moocs optical » moon optical, topics optical, atoms optical
patrick mons » patrick moyes, patrick bond, patrick mpondo
mons optical » ions optical, mono optical, lens 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 optical astronomy series ) OR ( the patrick mons optical ((astronomy sergey) OR (astronomy seven)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( the patrick moocs optical astronomy series ) or ( the patrick mons optical ((astronomy sergey) OR (astronomy seven)) ))".
• Adding a wildcard symbol may retrieve word variants: (( the patrick moocs optical astronomy series ) or ( the patrick mons optical ((astronomy sergey) OR (astronomy seven)) ))*.