Perhaps you should try some spelling variations:
optical astronomy » nautical astronomy, spherical astronomy, positional astronomy
astronomy surveys » astronomy survey, astronomy surveying, astronomy survives
patrick moocs » patrick moore, patrick mons, patrick moyes
moocs optical » moon optical, topics optical, cmos optical

You may be able to get more results by adjusting your search query.

• Adding a wildcard symbol may retrieve word variants: the patrick moocs optical astronomy surveys*.