Jacob Premselaar was married the first time to Wilhelmina Helena Paulina Maria Braasem. They had a child that survived the war. His second marriage was to Clara Groenteman.
Amsterdam municipal archive, Records Jokos, Möbel-claim 7611; property Joods Maatschappelijk Werk
In addition, a Jokos file (number 7611) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.