Perhaps you should try some spelling variations:
"engelhardt jan buchern" » "engelhardt john buchern", "engelhardt jr buchern", "engelhardt _ buchern", "engelhardt den buchern", "engelhardt man bucher"
"gebhard von buchern" » "gerhard von buchern", "gerard von buchern", "engelhard von buchern", "gebhard von burgern", "gebhard von lochern"

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: (("gebhard von buchern") OR ("engelhardt jan buchern")).
• Removing quotes may allow a broader search: (( gebhard von buchern ) or ( engelhardt jan buchern )).
• Adding a wildcard symbol may retrieve word variants: (("gebhard von buchern") or ("engelhardt jan buchern"))*.