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 astronomers"))) OR ("amateur astronomie")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"amateur astronomer\") OR (\"amateur astronomers\"))) or (\"amateur astronomie\"))".
• Removing quotes may allow a broader search: (((( amateur astronomer ) OR ( amateur astronomers ))) or ( amateur astronomie )).
• Adding a wildcard symbol may retrieve word variants: (((("amateur astronomer") OR ("amateur astronomers"))) or ("amateur astronomie"))*.