1. Luossavaara Kiirunavaara Aktiebolag (LKAB) website. https://www.lkab.com/en/about-lkab/from-mine-to-port/mining/.
2. Sustainable Underground Mining (SUM) website. https://sustainableundergroundmining.com/.
3. Mining Magazine (2018). Electric approach saves ventilation costs at Borden. https://www.miningmagazine.com/sustainability/news/1347608/electric-approach-saves-ventilation-costs-at-borden.
4. Arbetsmiljöverket, (2018). AFS 2018:1 Hygieniska gränsvärden (in Swedish). https://www.av.se/globalassets/filer/publikationer/foreskrifter/hygieniska-gransvarden-afs-2018-1.pdf.
5. European Union Commission (2017). Commission Directive