His son Albert Georg Sijthoff continued in his father's footsteps, taking over as publisher of the Haagsche Courant.
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The family's publishing company continues to operate today as Luitingh-Sijthoff.
Luitingh-Sijthoff, a Dutch publishing company passed down through the Sijthoff family
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Bob Sijthoff, descendant of Albertus Willem Sijthoff who sued Wikimedia in the Netherlands in 2008
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Albert Georg Sijthoff (1853–1927), son of Albertus Willem Sijthoff and publisher of the Haagsche Courant
In an article in Quote in July 2006, Jort Kelder states that a confidant of Willem Endstra told him that Sijthoff bought two pit houses in Amsterdam from Endstra in March 2001 through the mediation of Willem Holleeder.