Oskar Mayer was a son of Isaak Mayer and Luisa Kern. He married 23 December 1909 in Rheinböllen (G) to Rosa (Rosette) Kann who was born there, daughter of ?? Kann and Carolina Wolf. The couple had two children: Hedwig and Hans.
City Archive of Amsterdam, archive cards of Oskar Mayer, Rosette Kann (Kaan) an Hedwig Maijer.
In addition, a Jokos file (number 30431) on this person is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.