Perhaps you should try some spelling variations:
practical astronomy » optical astronomy, positional astronomy
astronomy sergey » astronomy survey, astronomy surveys, astronomy large
moocs practical » mics practical, abcs practical, ics practical
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 sergey ) OR ( the patrick nos nautical astronomy seven )).
• Adding a wildcard symbol may retrieve word variants: (( the patrick moocs practical astronomy sergey ) or ( the patrick nos nautical astronomy seven ))*.