Perhaps you should try some spelling variations:
astronomy series » gastronomy services, astronomy survives, astronomy studies
astronomy sergey » astronomy survey, astronomy surveys, astronomy large
moore practical » more practical, mouse practical, course practical
moocs practical » books practical, mics practical, colts practical
astronomy seven » astronomy some, astronomy science, astronomy between

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