Jacob Marcus was married to Vrouwtje Blom. The couple lived at 137 Brederostraat in Zwolle.
D. Stibbe and J. Hagedoorn, Herinneringsboek joods Zwolle 1940-1945 (Zwolle 1995) 48-49
In addition, a Jokos file (number 6677) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.