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

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