Another son, also named Jan, joined the Waffen-SS during World War II, and Pelser, his wife, and three sons all joined the Nationaal-Socialistische Beweging.
Joop Zoetemelk | Joop van Oosterom | Joop van den Ende | Joop Doderer | Joop den Uyl | Wolfgang Joop | Professor Pelser and a leaf of ''Senecio fistulosus | Joop Wijn | Joop van Wijk | Joop ter Heul | Joop Glimmerveen | Joop Boutmy |