User talk:2001:E68:5ED5:FF00:F075:5A2E:3836:E21F

July 2023
Please do not add or change content, as you did at List of metro systems, without citing a reliable source. Please review the guidelines at Citing sources and take this opportunity to add references to the article. Thank you. Nguyen QuocTrung (talk) 08:34, 3 July 2023 (UTC)