1. Mäkinen T (1994) Method for producing high-grade nickel matte and metallized sulfide matte. US Patent 5 332 414. July 26, 1994
2. Mäkinen T, Taskinen P (1997) Physical chemistry of direct high-grade nickel matte smelting. In: 8th International Flash Smelting Symposium, Tucson (AZ)-Salt Lake City (UT). Outokumpu, Espoo, pp 251–295
3. Mäkinen T, Taskinen P (2008) State of the art in nickel smelting: direct Outokumpu nickel technology. Trans IMM Sect C, 117(2):C86–94
4. Johto H, Latostenmaa P, Peuraniemi E, Osara K (2018) Review of operations at the Boliden Harjavalta nickel smelter. In: This conference
5. Diaz C, Landolt C, Vahed A, Warner AE, Taylor J (1988) A review of nickel pyrometallurgical operations. JOM 40(9):29–33