Sara Yzerkoper was a daughter of Samuel IJzerkoper and Dina Walvis. She married in Amsterdam on 21 November 1928 to Maurits Blits, son of Hijman Blits and Naatje Loeza.
City Archive of Amsterdam, archive card of Sara IJzerkoper and website www.wiewaswie.nl .
In addition, a Jokos file (number 52244) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.