"東京地方裁判所 平成元年(合わ)72号 判決 - 大判例" [Tokyo District Court Judgment No. 72 of 1989 - Grand precedent]. daihanrei.minorusan.net (in Japanese). Retrieved 25 April 2024.
newsee-media.com
"古田順子の生い立ちや両親の現在~飯島愛コンクリート事件関与のデマも総まとめ" [Junko Furuta's upbringing and the present of her parents-A summary of the hoaxes involved in the Ai Iijima Concrete Incident]. NewSee (in Japanese). 10 December 2019. Retrieved 1 January 2020.
newsmatomedia.com
"古田順子の両親の現在や生い立ち!女子高生コンクリート事件の被害者まとめ" [Junko Furuta's parents' current status and upbringing! Summary of victims of high school girl concrete incident]. MATOMEDIA [Matomedia]|Entertainment/gossip/incident summary (in Japanese). 4 January 2020. Retrieved 16 April 2021.
"JKコンクリート詰め41日間もまわされ続けた畜生事イ牛の全て。犯人達の現在がヤバすぎ・・・ ※実写化 動画あり※" [All of the animal cows that have been passed around for 41 days packed in JK concrete. The current state of the culprits is too dangerous...]. Samsara Bulletin (in Japanese). 19 October 2017. Retrieved 20 November 2019.
douga bubble (26 December 2017). 女子高生コンクリ殺人 当時の報道6 [Concrete murder of a high school girl Reported at the time 6] (in Japanese). Archived from the original on 9 December 2019. Retrieved 11 April 2019.
Some sources attest his first name as "Nobuharu", an alternate reading of the kanji伸治.
youtube.com
douga bubble (26 December 2017). 女子高生コンクリ殺人 当時の報道6 [Concrete murder of a high school girl Reported at the time 6] (in Japanese). Archived from the original on 9 December 2019. Retrieved 11 April 2019.