Cosman Kiek was a son of Louis Israel Kiek and Margaretha Citroen. He was married in Amsterdam on 17 August 1905 to Lea Meliono, a daughter of David Meliono and Marianne Schaap. Cosman and Lea had three children; Esther and David still lived with their mother. Louis Israel lived in the Apeldoornse Bos since 1 July 1932. Since 1924 Cosman and Lea did not live together anymore.
City Archive of Amsterdam, archive card of Lea Meliono, website www.wiewaswie.nl and an addition of a visitor of the website.