Perhaps you should try some spelling variations:
"amateur astronomie" » "amateur astronomy", "amateur astronomical", "amateur astronomer's"
"amateur astronomer" » "amateur astronomy"
"amateur astronomers" » "amateur astronomys"

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: (("amateur astronomer") OR ((("amateur astronomie") OR ("amateur astronomers")))).
• Removing quotes may allow a broader search: (( amateur astronomer ) or ((( amateur astronomie ) or ( amateur astronomers )))).
• Adding a wildcard symbol may retrieve word variants: (("amateur astronomer") or ((("amateur astronomie") or ("amateur astronomers"))))*.