Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy, positional astronomy
astronomy sergey » astronomy survey, astronomy surveys, astronomy seven
moocs practical » books practical, mics practical, colts practical
moore practical » more practical, mouse practical, course practical
mons practical » coins practical, bonds practical, boss practical
moocs nautical » logs nautical, nos nautical
patrick moocs » patrick moyes, patrick moore's
patrick mons » patrick moyes, patrick bond, patrick mpondo
hoc nautical » nos nautical, hoc analytical, logs 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 mons practical astronomy sergey ))) OR ( the patrick moore practical astronomy sergey ))) OR ( the patrick ((moocs nautical) OR (hoc 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 mons practical astronomy sergey ))) or ( the patrick moore practical astronomy sergey ))) or ( the patrick ((moocs nautical) OR (hoc nautical)) astronomy sergey ))".
• Adding a wildcard symbol may retrieve word variants: (((((( the patrick moocs practical astronomy sergey ) or ( the patrick mons practical astronomy sergey ))) or ( the patrick moore practical astronomy sergey ))) or ( the patrick ((moocs nautical) OR (hoc nautical)) astronomy sergey ))*.