GB 190200698, Ostwald, Wilhelm, "Improvements in the Manufacture of Nitric Acid and Nitrogen Oxides", diterbitkan tanggal January 9, 1902, dikeluarkan tanggal March 20, 1902
GB 190208300, Ostwald, Wilhelm, "Improvements in and relating to the Manufacture of Nitric Acid and Oxides of Nitrogen", diterbitkan tanggal December 18, 1902, dikeluarkan tanggal February 26, 1903