Alexander Kosman was married to Sophia Sanders. He was a real estate agent.
K. Ribbens, Zullen we nog terugkeren
. De jodenvervolging in Amersfoort tijdens de Tweede Wereldoorlog (Amersfoort 2002) 168-171
In addition, a Jokos file (number 30784) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.