Marcus Velleman (Hartog Velleman and Saartje Hoogstraal) married 17 Feb 1916 in Groningen to:
Betje van Gelder (Lazarus van Gelder and Esther van Zanten).
Betje passed away 21-07-1934 in Groningen
Marcus and Betje had 2 children:
1) Sara Simons-Velleman 14 Nov 1916 Groningen-12 Oct 1942 Auschwitz
2…
In addition, a Jokos file (number 81) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.