Perhaps you should try some spelling variations:
optical astronomy » nautical astronomy, spherical astronomy
astronomy sergey » astronomy survey, astronomy surveys, astronomy large
astronomy seven » astronomy some, astronomy science, astronomy between
moore optical » moire optical, more optical, core optical
m positional » _ positional, 8 positional, a positional
patrick m » patrick _, patrick a

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 optical astronomy sergey ) OR ( the patrick m positional astronomy seven )).
• Adding a wildcard symbol may retrieve word variants: (( the patrick moore optical astronomy sergey ) or ( the patrick m positional astronomy seven ))*.