Perhaps you should try some spelling variations:
practical astronomy » optical astronomy, positional astronomy
critical astronomy » optical astronomy, tropical astronomy, classical astronomy
astronomy sergey » astronomy survey, astronomy surveys, astronomy seven
moocs practical » books practical, mics practical, colts practical
patrick moocs » patrick moore, patrick mons, patrick moyes
love nautical » logs nautical, some nautical, love critical
some critical » some practical
patrick love » patrick late, patrick le, patrick lord
patrick some » patrick home, patrick sole, trick some

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 love nautical astronomy sergey ) OR ( the patrick some critical astronomy sergey )))).
• Adding a wildcard symbol may retrieve word variants: (( the patrick moocs practical astronomy sergey ) or ((( the patrick love nautical astronomy sergey ) or ( the patrick some critical astronomy sergey ))))*.