1. Report of Nickel in the European Union, Nickel Institute, available at: http://www.nickelinstitute.org/en/MediaCentre/Publications/NickelIntheEuropeanUnion.aspx
2. Cardiovascular Effects of Nickel in Ambient Air
3. F. W. Sunderman, Jr. , F.Coulston, G. L.Eichhorn, J. A.Fellows, E.Mastromatteo, H. T.Reno, M. H.Samitz, B. A.Curtis, B. L.Vallee, P. W.West, J. C.McEwan, S. I.Shibko and T. D.Boaz, Jr., Nickel, National Academy of Sciences, Washington, 1975, p. 277