1. Mäkipirtti, S. (Dissertation), “On the Sintering of W-Ni-Cu Heavy Metal,” Acta Polytech. Scand., Mech. Eng. Ser. 7: 1959.
2. Mäkipirtti, S., “On the Sintering of W-Ni-Cu Heavy Metal,” in: W. Leszynski (ed.), Powder Metallurgy (New York), 1961.
3. Metalworking News, Jan. 15, 1964.
4. Cf. Lenel, F. V., et al., “The Influence of Gravity in Sintering,” Trans. AIME227: 640–644 (1963).
5. Evans, P. E., and D. W. Ashell, “Grain Growth in Sintered Nickel Powder,” Intern. J. Powder Metallurgy
1: 36(1965).