1. L.N. Vauquelin, Ann. Chim. (Paris), 26 (1798), pp. 155, 170, 259; 30 (1799), p. 82.
2. F. Wöhler, Pogg. Ann., 13 (1828), p. 577.
3. A.A.B. Bussy, J. Chim. Med. Pharm. Toxicol., 4 (1828), p. 453.
4. G. Masing and O. Dahl, Wiss. Veröff. Seimens Werke, 8 (1929), p. 126.
5. Gerald Friedman, “Methods of Forming Powdered Metal Articles,” U.S. patent 4,772,450 (20 September 1988).