Perhaps you should try some spelling variations:
"astronomy and astrophysics summary" » "astronomy and astrophysics gamma", "astronomy and astrophysics sun", "astronomy and physics summary"
"astronomy and astrophysics stars" » "astronomy and astrophysics saas", "astronomy and astrophysics history", "astronomy and astrophysics sun"
"astronomy and astrophysics state" » "astronomy and astrophysics data", "astronomy and astrophysics saas", "astronomy and astrophysics chapter"

Try widening your search to All Fields.

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: (("astronomy and astrophysics summary") OR ((("astronomy and astrophysics stars") OR ("astronomy and astrophysics state")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"astronomy and astrophysics summary\") or (((\"astronomy and astrophysics stars\") OR (\"astronomy and astrophysics state\"))))".
• Removing quotes may allow a broader search: (( astronomy and astrophysics summary ) or ((( astronomy and astrophysics stars ) OR ( astronomy and astrophysics state )))).
• Adding a wildcard symbol may retrieve word variants: (("astronomy and astrophysics summary") or ((("astronomy and astrophysics stars") OR ("astronomy and astrophysics state"))))*.