# External source check (CUPED-PRE-20260831)

Checked 2026-09-04 with `scripts/verify-external-sources.py` (GET, follow redirects, 25s timeout). None of these pages audited this fixture. Machine log: [`external-source-check-CUPED-PRE-20260831.json`](./external-source-check-CUPED-PRE-20260831.json).

| Source | Requested URL | Final URL | HTTP | Title SHA-256 | Note | Use |
|---|---|---|---|---|---|---|
| Deng et al. CUPED paper | https://www.microsoft.com/en-us/research/publication/improving-the-sensitivity-of-online-controlled-experiments-by-utilizing-pre-experiment-data/ | https://www.microsoft.com/en-us/research/publication/improving-the-sensitivity-of-online-controlled-experiments-by-utilizing-pre-experiment-data/ | 404 | dd5d1ab959cb5541 | http 404 | Original method source for pre-experiment covariance adjustment |
| Statement on Statistical Significance and P-Values | https://www.amstat.org/asa/files/pdfs/p-valuestatement.pdf | https://www.amstat.org/asa/files/pdfs/p-valuestatement.pdf | 200 | — |  | Interpretation limits for p-values |
| e-Handbook of Statistical Methods | https://www.itl.nist.gov/div898/handbook/ | https://www.itl.nist.gov/div898/handbook/ | 200 | d4a4bc3e6e009d42 |  | General experimental-design and statistical reference |
| SEC | https://www.sec.gov/ | https://www.sec.gov/ | 200 | af14ad6191cce91b |  | Disclosure, baseline, and adjustment analogies |
| ISO 42001 | https://www.iso.org/standard/81279.html | https://www.iso.org/standard/81279.html | 403 | 301dc171e5fa8c5f | http 403 | Documentation and preprint context |

Keep original requested URLs. Re-check at decision time.