"Nederland, Indexen van de Archieven, Primaire Archiefstukken (BS en DTB), 1600-2000," database, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:QLZ4-65NN : 16 November 2020), Elisabeth CatharinA Geertruida Propper in entry for Wilhelmina Fredrika Monne, Birth 10 Jul 1900, Utrecht, Nederland; from database, openarchives (https://www.openarch.nl : 2016); citing Utrecht, archive 481, inventory number 148-02, record number 1761; ; Het Utrechts Archief.