Perhaps you should try some spelling variations:
"arthur robert van hippel" » "arthur robert v hippel", "arthur robert von hippel", "arthur robert van poppel", "arthur robert van impel"
"arthur robert von popper" » "arthur robert v popper", "arthur robertson von popper", "arthur robert vyner popper", "arthur robert n popper"

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: (("arthur robert van hippel") OR ("arthur robert von popper")).
• Removing quotes may allow a broader search: (( arthur robert van hippel ) or ( arthur robert von popper )).
• Adding a wildcard symbol may retrieve word variants: (("arthur robert van hippel") or ("arthur robert von popper"))*.