Perhaps you should try some spelling variations:
practical astronomy » optical astronomy, positional astronomy
astronomy sergey » astronomy surveys, astronomy seven, astronomy large
astronomy survey » astronomy surveys, autonomy survey, astronomy surveying
moocs practical » mics practical, does practical, drops practical
moore nautical » board nautical, moore national, some nautical
patrick moocs » patrick mons, patrick moyes, patrick moore's
mile nautical » i nautical, ii nautical, some nautical
patrick mile » patrick miller, patrick riley, patrick maill

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