https://www.bruegel.org/policy-brief/european-union-gas-survival-plan-2023
https://www.ips-journal.eu/topics/european-integration/europe-needs-to-spend-its-money-better-7243/
https://www.bwb.gv.at/fileadmin/user_upload/Abschlussbericht_BU_Kraftstoffe_2022_final_barrierefrei.pdf