1. NOW website. https://www.nwowhv.de/c/index.php/en/facilities/tank-farm.
2. EBV website. http://www.ebv-oil.org/cms/pdf/EBV_Informationsbroschuere_dba.pdf.
3. Strategic Petroleum Reserve. Department of Energy. https://www.energy.gov/fe/services/petroleum-reserves/strategic-petroleum-reserve.
4. Surbana Jurong website. https://surbanajurong.com/sector/jurong-rock-caverns/.