2000. ------. [LARSON, A. T.] Ammonia Synthesis. United States Patent 1,667,323, Apr. 24, 1928. Chem. Abs., vol. 22, 1928, p. 2035.

Fe oxide and the oxides of Mg and Na are used in a process similar to that described in United States Patent 1,667,322 (abs. 1999).