Clara Polak was a daughter of Aron Polak from Leeuwarden and Esther Bierschenk from Amsterdam. She married Salomon (Sallie) Waterman on 19 May 1937 in Amsterdam, a son of Alexander Waterman and Marianne van Velzen.
City Archive of Amsterdam, archive card of Clara Polak and Marianne van Velzen .
In addition, a Jokos file (number 11037) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.