Juda Monas was a son of Moses Monas and Rachel Delmonte. He married Rachel Vleesdrager in 1907 in Amsterdam. Stadsarchief Amsterdam, archiefkaart Juda Monas
In addition, a Jokos file (number 10609) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.