Abraham Ketellapper, a son of Isaac Ketellapper and Klaartje Halverstad, married 25 July 1928 in Amsterdam to Clara Lootsteen, a daughter of Isaac Lootsteen and Rebecca Ossendrijver. website www.wiewaswie.nl.
In addition, a Jokos file (number 18087) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.