Joseph Leendert van Gelder, miner in Oberhausen (Germany), was a son of Leendert Joseph van Gelder and Henderina van Vriesland. He married Rozetta van Gelder in Assen on 9 September 1903, a daughter of Salomon van Gelder and Folgeltje de Lange. The couple had five children: Fogeltje, Salomon, Hendri…
In addition, a Jokos file (number 60142) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.