«La documentazione essenziale per l'attribuzione della scoperta». Arxivat de l'original el 25 febrer 2017. [Consulta: 24 febrer 2014]. «A later request was presented to the Patent Office of the Reign of Piedmont, under No. 700 of Volume VII of that Office. The text of this patent request is not available, only a photo of the table containing a drawing of the engine. This may have been either a new patent or an extension of a patent granted three days earlier, on 30 December 1857, at Turin.»
«La documentazione essenziale per l'attribuzione della scoperta». Arxivat de l'original el 25 febrer 2017. [Consulta: 24 febrer 2014]. «A later request was presented to the Patent Office of the Reign of Piedmont, under No. 700 of Volume VII of that Office. The text of this patent request is not available, only a photo of the table containing a drawing of the engine. This may have been either a new patent or an extension of a patent granted three days earlier, on 30 December 1857, at Turin.»
