1. Sensitivity and specificity of the nickel spot (dimethylglyoxime) test
2. European Parliament and Council Directive 94/27/EC of 30 June 1994 amending for the 12th time Directive 76/769/EEC on the approximation of the laws, regulations and administrative provisions of the Member States relating to restrictions on the marketing and use of certain dangerous substances and preparations (the EU Nickel Directive);Official J Eur Union,1994
3. Commission Regulation (EC) No. 552/2009 of 22 June 2009 amending Regulation (EC) No. 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) as regards Annex XVII. Annex: Entry 27;Official J Eur Union,2009
4. European Chemicals Agency (ECHA).Prolonged contact with the skin—definition building for nickel 02.04.2014.Helsinki Finland ECHA 2014.https://echa.europa.eu/documents/10162/13641/nickel_restriction_prolonged_contact_skin_en.pdf. Accessed October 25 2017).