[1] https://www.consilium.europa.eu/en/infographics/gas-storage-capacity/
[3] Gas Infrastructure Europe, GIE
[4] AGSI+
[5] https://interfax.com/newsroom/top-stories/82212/
[6] https://erdgasspeicher.de/en/gas-storage/gas-storage-capacities/
[7] https://www.energymonitor.ai/tech/energy-storage/weekly-data-european-gas-storage-is-filled-to-67