Thanks to our good relationships with our Ukrainian partner we have received really valuable for us copies of the certificates signed by Maria Sklodowska-Curie . The originals are at the Institute of the Academy of Sciences in Kharkov (ДЕРЖАВНА УСТАНОВА« ІНСТИТУТ МЕДИЧНОЇ РАДІОЛОГІЇ ІМ. С.П. ГРИГОР'ЄВА НАЦІОНАЛЬНОЇ АКАДЕМІЇ МЕДИЧНИХ НАУК УКРАЇНИ) . Certificates are written in French and have original signatures, one was issued on 12th February 1925, the second on 14tth October 1927. Both concern the content of radioactive radium in the substance.
There is also the third document, in English, certificate of origin, issued on 19th February 1925 by the Union Minière du Haut Katanga.