Rao, P.K.; Bhaskarasarma, P.V.R.; Tripathy, A.K.; Jena, P.K.(Transactions Of The Institution Of Mining And Metallurgy Section C-Mineral Processing And Extractive Metallurgy, 88(SEP), 1979: C187-C190)
Paramguru, R.K.; Bose, S.K.; Sircar, S.C.(Transactions Of The Institution Of Mining And Metallurgy Section C-Mineral Processing And Extractive Metallurgy, 88(SEP), 1979: C197-C202)