1. Pliny, C.P.S. (circa 70). Natural History Book 33, 21.
2. Agricola, G. (1556). De Re Metallica Trans Hoover, H.C. and Hoover, L.H., Dover Publications, N.Y. 1950 Book XIII.
3. Mills, C. (1978). Process Design, Scale-Up and Plant Design for Gravity Concentration. In Mular, A.L. and Bhappu, R.B. (Eds.). Mineral Processing Plant Design AIME New York, Chapter 18 404–426.
4. Burt, R.O. and Mills, C. (1982). Gravity Concentration — a process at the Crossroads. Paper presented at 111th Meeting of the Am. Inst. Min. Eng. Dallas, February
5. Nio, T.H. (1978). Mineral Dressing by IHC Jigs. Paper presented at Gravity Separation Short Course. Reno, Nv. 46 pp.