Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy, positional astronomy
astronomy between » antinomy between, economy between
astronomy series » gastronomy services, astronomy survives, astronomy studies
astronomy sergey » astronomy survey, astronomy surveys, astronomy large
moocs practical » mics practical, abcs practical, ics practical
astronomy seven » astronomy some, astronomy science, astronomy section
moocs nautical » hoc nautical, logs nautical
patrick moocs » patrick moore, patrick mons, patrick moyes
nos nautical » logs nautical, hoc nautical, some nautical

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