Need Help Finding Causal Inference Whitepaper for Impact Reports

hi all, I was planning on reading more on Impact reports to understand the underlying math better, got to this page https://docs.mixpanel.com/docs/reports/apps/impact which links to https://mixpanel.box.com/v/causal-inference-whitepaper but that's a dead link... does anyone know where the whitepaper is or where else I can find this information?