Elie Salomon Kets de Vries married Jansje Hamburger in 1918 in Amsterdam. She died in 1931. He had with her the two sons mentioned here. In 1936 he married Klara Marx and had another son with her. From 1938 they lived seperately.
Stadsarchief Amsterdam, archiefkaart Elie Salomon Kets de Vries