# A surprising formula for Sobolev norms

> Research article (Proceedings of the National Academy of Sciences, 2021) · cited 51× · AI/ML

**Wikidata**: [openalex:W3130926264](https://www.wikidata.org/wiki/openalex:W3130926264)  
**Source**: https://4ort.xyz/entity/a-surprising-formula-for-sobolev-norms