diff --git a/🧠-Educational.md b/🧠-Educational.md
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 * [Mission US](https://www.mission-us.org/) - American History Learning Games
 * [OnThisDay](https://www.onthisday.com/) or [Curiosity Of The Day](https://www.curiosityoftheday.com/) - What Happened on Specific Days
 * [Royal Constellations](https://royalconstellations.visualcinnamon.com/) - Royal Family Ancestral Visualization
-* [Sciphilos](https://sciphilos.info/) or [Calculating Empires](https://calculatingempires.net/) - Historical Discovery Timelines
+* [⁠Historical Tech Tree](https://www.historicaltechtree.com/) or [Calculating Empires](https://calculatingempires.net/) - Historical Discovery / Tech Timelines
 * [ETHW](https://ethw.org/) - Engineering and Technology History Wiki
 * [Royal Armouries Collections](https://royalarmouries.org/collection/) - Ancient Armaments Museum
 * [NuclearWeaponArchive](https://nuclearweaponarchive.org/) - Nuclear Weapons History