Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy, positional astronomy
astronomy sergey » astronomy surveys, astronomy large, astronomy society
astronomy survey » astronomy surveys, autonomy survey, astronomy surveying
moocs practical » books practical, mics practical, colts practical
astronomy seven » astronomy some, astronomy science, astronomy between
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 sergey ) OR ( the patrick moocs practical astronomy seven ))) OR ( the patrick moocs practical astronomy survey ))) OR ( the patrick ((moocs nautical) OR (nos nautical)) astronomy sergey )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((((( the patrick moocs practical astronomy sergey ) or ( the patrick moocs practical astronomy seven ))) or ( the patrick moocs practical astronomy survey ))) or ( the patrick ((moocs nautical) OR (nos nautical)) astronomy sergey ))".
• Adding a wildcard symbol may retrieve word variants: (((((( the patrick moocs practical astronomy sergey ) or ( the patrick moocs practical astronomy seven ))) or ( the patrick moocs practical astronomy survey ))) or ( the patrick ((moocs nautical) OR (nos nautical)) astronomy sergey ))*.