"【もうそんな時代か…】721系の解体を開始【JR北海道】" [[Is it that time already?] Dismantling of 721 series begins [JR Hokkaido]]. RM News (in Japanese). Japan: Neko Publishing. 29 August 2023. Retrieved 24 April 2024.
"【解体待ちか？】721系F-4編成苗穂工場入場" [[Awaiting demolition?] 721 series set F-4 entered Naebo factory]. RM News (in Japanese). Japan: Neko Publishing. 11 April 2024. Retrieved 10 May 2024.
"【JR北海道】721系F-3015編成が苗穂工場へ廃車入場" [[JR Hokkaido] 721 series set F-3015 enters Naebo factory for scrapping]. RM News (in Japanese). Japan: Neko Publishing. 25 April 2024. Retrieved 10 May 2024.
mynavi.jp
news.mynavi.jp
JR北海道、733系増備で721系置換え - 新幹線札幌開業後に速達化も [JR Hokkaido to replace 721 series with additional 733 series trains - Speeding up service after opening of Sapporo Shinkansen line]. Mynavi News (in Japanese). 4 April 2024. Retrieved 10 May 2024.
