1. Mason, B.; Moore, C.B.Principles of Geochemistry, 4th ed.; John Wiley & Sons, New York, 1982.
2. Nriagu, J.O. Global Metal Pollution: Poisoning the Biosphere?Environment1990,32(7), 7–11, 28-32.
3. U.S. Environmental Protection Agency.Locating and Estimating Air Emissions from Sources of Nickel; Office of Air Quality Planning and Standards, Research Triangle Park, NC, March 1984, EPA-450/4-84-007f.
4. Nickel Producers Environmental Research Association (NiPERA).Occupational Exposure Limits Criteria Document for Nickel and Nickel Compounds, Volume 1: Summary, Conclusions, and Recommendations; Prepared for the European Commission, Directorate-General V, Public Health and Safety at Work Directorate. Prepared by NiPERA in collaboration with Eurometaux, Dec 24, 1996.
5. U.S. Environmental Protection Agency.Documentation for the 1996 Base Year National Toxics Inventory for On-Road Sources; Emission Factor and Inventory Group (MD-14); Emissions, Monitoring, and Analysis Division, Research Triangle Park, NC, June 2000.