Ercan (2016-01-07). Die besten Handytarife- mit und ohne Handy (in de). tegget.de / markt.de GmbH & Co. KG. Retrieved on 2016-01-21.web.archives.org
Suzanne Smalley (2023-12-12). FCC reminds mobile phone carriers they must do more to prevent SIM swaps (in de). therecord.media. Retrieved on 2024-01-17.web.archives.org