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

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