1. Investigations on the quantitative determination of nickel and chromium in human lung tissue;Raithel;Int. Arch. Occup. Environ. Health,1988
2. International Agency for Research on Cancer website, monographs on the evaluation of carcinogenic risks to humans. http://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Evaluation-Of-Carcinogenic-Risks-To-Humans/Arsenic-Metals-Fibres-And-Dusts-2012. IARC Monographs (last Accessed 8 March 2016).
3. International Agency for Research on Cancer website monographs on the evaluation of carcinogenic risks to humans. http://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Evaluation-Of-Carcinogenic-Risks-To-Humans/Inorganic-And-Organic-Lead-Compounds-2006. IARC Monographs (last Accessed 8 March 2016).
4. International Agency for Research on Cancer website monographs on the evaluation of carcinogenic risks to humans. http://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Evaluation-Of-Carcinogenic-Risks-To-Humans/Cobalt-In-Hard-Metals-And-Cobalt-Sulfate-Gallium-Arsenide-Indium-Phosphide-And-Vanadium-Pentoxide-2006. IARC Monographs (last Accessed 8 March 2016).
5. International Agency for Research on Cancer website monographs on the evaluation of carcinogenic risks to humans. http://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Evaluation-Of-Carcinogenic-Risks-To-Humans/Beryllium-Cadmium-Mercury-And-Exposures-In-The-Glass-Manufacturing-Industry-1993. IARC Monographs (last Accessed 8 March 2016).