Board Game Arena

Hi,

Does anyone have a link where I can find the rules for all the extensions?

Thanks

They are all on the game page.
https://boardgamearena.com/gamepanel?game=stoneage
Click on see more below the main rules download button.
You also have the wiki page. The French and English version of the wiki page have a summary of the rules of each expansion. English version:
https://en.doc.boardgamearena.com/Gamehelpstoneage