[1] ETS 300 706 - Enhanced Teletext specification - ets_300706e01p.pdf, 2000-02-02T20:07:05.000Z, 2020-10-25T01:13:48.184Z https://www.etsi.org/deliver/etsi_i_ets/300700_300799/300706/01_60/ets_300706e01p.pdf

[2] World System Teletext - Wikipedia, 2020-12-03T15:26:32.000Z, 2020-12-05T05:17:50.170Z https://en.wikipedia.org/wiki/World_System_Teletext

[3] Wayback Machine, 2020-12-05T05:18:15.000Z https://web.archive.org/web/20160326062859/https://www.phecap.nl/download/enhenced-teletext-specs.pdf

[4] ≠ Teletex

[5] 25_524.pdf, 2022-12-11T07:40:06.000Z https://www.jstage.jst.go.jp/article/sicejl1962/25/6/25_6_524/_pdf