1. Graedel, T.E., Erdmann, L.: Will metal scarcity impede routine industrial use? MRS Bull. 37, 325–331 (2012)
2. European Commission: Communication from the commission to the European Parliament, the Council, the European economic and social Committee and the Committee of the regions: tackling the challenges in commodity markets and on raw materials. https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=COM:2011:0025:FIN:en:PDF (2011). Accessed 8 Oct 2019
3. European Commission: Communication from the commission to the European Parliament, the Council, the European economic and social Committee and the Committee of the regions: on the review of the list of critical raw materials for the EU and the implementation of the Raw Materials Initiative. https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:52014DC0297&from=EN (2014). Accessed 8 October 2019
4. European Commission: Communication from the commission to the European Parliament, the Council, the European economic and social Committee and the Committee of the regions: on the 2017 list of critical raw materials for the EU. https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:52017DC0490&from=EN. (2017). Accessed 8 Oct 2019
5. Løvika, A.N., Hagelüken, C., Wägera, P.: Improving supply security of critical metals: current developments and research in the EU. Sustain Mater Technol 15, 9–18 (2018)