Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy
optical astronomy » nautical astronomy, spherical astronomy
astronomy sergey » astronomy surveys, astronomy seven, astronomy large
astronomy survey » astronomy surveys, autonomy survey, astronomy surveying
more positional » more positioning, aware positional, more conditional
pure positional » aware positional, pure conditional, pure rotational
mkie practical » more practical, made practical, make practical
patrick mode » patrick moore, patrick moyes, patrick mons
mode optical » wave optical
patrick mkie » patrick mackie, patrick mein, patrick moore
patrick more » patrick moore, patrick moyes, patrick mark
patrick pure » patrick burke, patrick part, patrick burk

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 mode optical astronomy sergey ) OR ((( the patrick mkie practical astronomy sergey ) OR ((( the patrick more positional astronomy sergey ) OR ( the patrick pure positional astronomy survey )))))).
• Adding a wildcard symbol may retrieve word variants: (( the patrick mode optical astronomy sergey ) or ((( the patrick mkie practical astronomy sergey ) or ((( the patrick more positional astronomy sergey ) or ( the patrick pure positional astronomy survey ))))))*.