Perhaps you should try some spelling variations:
practical astronomy » optical astronomy, positional astronomy
astronomy surveys » astronomy survey, astronomy surveying, astronomy survives
astronomy sergey » astronomy survey, astronomy seven, astronomy large
moocs practical » mics practical, abcs practical, ics practical
patrick moocs » patrick moore, patrick mons, patrick moyes
n nautical » _ nautical, a nautical, i nautical
2 nautical » _ nautical, a nautical, 200 nautical
patrick n » patrick _, patrick a, patrick d
patrick 2 » patrick _, patrick a, patrick d

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 n nautical astronomy sergey ) OR ( the patrick 2 nautical astronomy sergey ))) OR ( the patrick n nautical astronomy surveys )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( the patrick moocs practical astronomy sergey ) or ((((( the patrick n nautical astronomy sergey ) OR ( the patrick 2 nautical astronomy sergey ))) or ( the patrick n nautical astronomy surveys ))))".
• Adding a wildcard symbol may retrieve word variants: (( the patrick moocs practical astronomy sergey ) or ((((( the patrick n nautical astronomy sergey ) OR ( the patrick 2 nautical astronomy sergey ))) or ( the patrick n nautical astronomy surveys ))))*.