Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy, positional astronomy
astronomy survey » astronomy surveys, astronomy sergey, autonomy survey
astronomy during » astronomy dialling, astronomy meeting, economy during
moocs practical » mics practical, clocks practical, colts practical
patrick moocs » patrick moore, patrick mons, patrick moyes
de optical » de optica, mode optical, edge optical
e optical » e optimal, mode optical, core optical

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 survey ) OR ( the patrick ((de optical) OR (e optical)) astronomy during )).
• Adding a wildcard symbol may retrieve word variants: (( the patrick moocs practical astronomy survey ) or ( the patrick ((de optical) or (e optical)) astronomy during ))*.