1. Standen A, Kirth-Othmer Enc Chem Tech 9 (1966) 380.
2. Lotter N O and Bradshaw D J, Miner Eng 23 (2010) 945.
3. Glembotskii V A, TsvetnyeMetally 4 (1958) (S. Vynogradova, Trans.) 6 (in Russian).
4. Plaskin I N and Zaitseva S P, (Mintek translation no. 1295, 1988). Naachnye Soobsh cheniya Institute GonnogodelaImeni AA kochinskogo, AkademiyaNauk SSSR, Moskva 6 (1960) 15.
5. Bradshaw D J, Harris P J and Connor C T O, South African Institute of Mining and Metallurgy, (1998) 189.