(in Dutch) Suèr, Henk. "Joop den Uyl: verguisd en inspirerend" [Joop den Uyl: maligned and inspiring] (PDF) (in Dutch). Archived from the original(PDF) on 5 March 2012. Retrieved 17 April 2010.. roodkoper.nl
"Onthullende biografie Joop den Uyl" [Revealing biography of Joop den Uyl] (in Dutch). Archived from the original on 27 June 2009. Retrieved 17 April 2010.. University of Amsterdam. 21 February 2008
(in Dutch) Suèr, Henk. "Joop den Uyl: verguisd en inspirerend" [Joop den Uyl: maligned and inspiring] (PDF) (in Dutch). Archived from the original(PDF) on 5 March 2012. Retrieved 17 April 2010.. roodkoper.nl
"Onthullende biografie Joop den Uyl" [Revealing biography of Joop den Uyl] (in Dutch). Archived from the original on 27 June 2009. Retrieved 17 April 2010.. University of Amsterdam. 21 February 2008