Grand Medaille d'Ór Paris. Certificate, correspondence and speech Dudok.Various diplomas and certificatesVarious diplomas and certificatesVarious diplomas and certificatesVarious diplomas and certificatesCertificates and diplomasCertificates and diplomasLithograph - Design of a certificate commemorating the laying of a memorial stone in the Zuiderzee locks at Schellingwoude (Oranjesluizen).Certificate Contest Craftsmen Amsterdam,Various charters