Future Androids 17 and 18 → Future Chiaotzu
Future Trunks reports that Chiaotzu died in battle against the androids. The report does not identify whether Android 17 or Android 18 delivered the fatal attack. They are initially described as Androids 19 and 20, but the opponents in the future are later confirmed to be Androids 17 and 18.
SourceChapter 335 — A Message of Terror (Japanese: 恐怖のメッセージ)Full Color Androids and Cell Arc, Vol. 1 · Akira Toriyama / Shueisha
Additional sourceChapter 348 — To the Laboratory...!! (Japanese: 研究所へ…!!)Full Color Androids and Cell Arc, Vol. 2 · Akira Toriyama / Shueisha
Additional sourceChapter 350 — Androids 17 and 18, and...16 (Japanese: 17号・18号、そして…16号)Full Color Androids and Cell Arc, Vol. 2 · Akira Toriyama / Shueisha