(in German) Web site of the Kurt-Haertel-Institut für geistiges Eigentum an der FernUniversität in Hagen, Kurt HaertelArchived 2007-11-09 at the Wayback Machine. Consulted on January 28, 2007.
IP Hall of Fame 2006, "Kurt Härtel". Archived from the original on October 3, 2007. Retrieved 2017-05-09.{{cite web}}: CS1 maint: bot: original URL status unknown (link).
(in German) Web site of the Kurt-Haertel-Institut für geistiges Eigentum an der FernUniversität in Hagen, Kurt HaertelArchived 2007-11-09 at the Wayback Machine. Consulted on January 28, 2007.