Perhaps you should try some spelling variations:
"johannes dieter muller" » "johannes dietlein muller", "johannes pfister muller", "johannes richter muller", "johannes dietmar muller", "johannes peter muller", "johannes gunter muller"
"johann peter miller" » "johann peter muller", "johann feuer miller", "johann der miller"

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: (("johannes dieter muller") OR ((("johann peter miller") OR ("johann peter koller")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"johannes dieter muller\") or (((\"johann peter miller\") OR (\"johann peter koller\"))))".
• Removing quotes may allow a broader search: (( johannes dieter muller ) or ((( johann peter miller ) OR ( johann peter koller )))).
• Adding a wildcard symbol may retrieve word variants: (("johannes dieter muller") or ((("johann peter miller") OR ("johann peter koller"))))*.