1. Otto R., 2002, “Bismuth — the new ecologically green metal for modern lubricating engineering”, Industrial Lubrication and Tribology, 54(4), pp. 153–164.
2. Stephen V.D., Paul D.F., 1991, “Chemistry of the Extreme-Pressure Lubricant Additive Lead Naphthenate on Steel Surfaces,” Langmuir, 7, pp. 2981–2990.
3. Yao J., Dong, J., 1994, “Antiwear synergism of borates and copper oleate”, Lubrication Engineering, 50, pp. 657–663.
4. Richard W.H., 2000, “Evaluation of Bismuth Naphthenate as an EP Additive”, Lubrication Engineering, 2000, 56, pp. 45–51.
5. Rohr O., 1993, “Bismuth, a New Metallic but Non-Toxic Replacement for Lead as EP-Additive in Grease”, NLGI Spokeman, 57(2), pp. 50–57.