- Overprints (including Cuypers' design, which was rejected by 97 votes to 5 and the approved design, fine);
Various printings criticizing the choice of the design N.O., dated 1864;
- Photocopies of documents concerning the monument, from: 'De Nederlandsche Spectator' and the 'Bouwkundige Bijdragen', dating 1865, 1868.