Perhaps you should try some spelling variations:
"very sparse telescopes" » "very space telescope", "very star telescopes", "very state telescopes"
"very large telescopes" » "very large telescope", "very radio telescopes"
"very space telescopes" » "very space telescope", "very scarce telescopes", "query space telescopes", "key space telescopes"

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: (("very large telescopes") OR ((("very space telescopes") OR ("very sparse telescopes")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"very large telescopes\") or (((\"very space telescopes\") OR (\"very sparse telescopes\"))))".
• Removing quotes may allow a broader search: (( very large telescopes ) or ((( very space telescopes ) OR ( very sparse telescopes )))).
• Adding a wildcard symbol may retrieve word variants: (("very large telescopes") or ((("very space telescopes") OR ("very sparse telescopes"))))*.