Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, optical astronomy, positional astronomy
astronomy series » gastronomy services, astronomy survives, astronomy studies
astronomy sergey » astronomy survey, astronomy surveys, astronomy seven
moocs practical » mics practical, abcs practical, ics practical
drops practical » aris practical, devops practices, arrays practical
patrick mpondo » patricia opondo, patrick bond
patrick mons » patrick moyes, patrick bond, patrick timony

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