The International Nickel Study Group (INSG) is an intergovernmental organization established in June 1990, in The Hague, Netherlands, within the framework of the United Nations. Since 2006, the International Copper Study Group and International Lead and Zinc Study Group have been co-located with INSG in Lisbon, Portugal.Headquarters Agreement Between the Portuguese Republic and the International Copper Study Group, the International Lead and Zinc Study Group and the International Nickel Study Group, Diário da República, 1ª série / N.º 234 (2006) (pp. 8231–8235). Accessed 6 April 2022. https://files.dre.pt/1s/2006/12/23400/82268235.pdf
