Perhaps you should try some spelling variations:
practical astronomy » positional astronomy
optical astronomy » spherical astronomy, positional astronomy
astronomy survey » astronomy surveys, astronomy sergey, autonomy survey
astronomy seven » astronomy some, astronomy science, astronomy between
patrick moocs » patrick moore, patrick mons, patrick moyes
nos nautical » logs nautical, hoc nautical, some nautical
patrick nos » patrick nomo, patrick bas, patrick n

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 ((practical astronomy) OR (optical astronomy)) sergey ) OR ((( the patrick nos nautical astronomy survey ) OR ( the patrick nos nautical astronomy seven )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( the patrick moocs ((practical astronomy) OR (optical astronomy)) sergey ) or ((( the patrick nos nautical astronomy survey ) or ( the patrick nos nautical astronomy seven ))))".
• Adding a wildcard symbol may retrieve word variants: (( the patrick moocs ((practical astronomy) OR (optical astronomy)) sergey ) or ((( the patrick nos nautical astronomy survey ) or ( the patrick nos nautical astronomy seven ))))*.