# Jacob Ridder

> Ph.D. Universiteit Utrecht 1921

**Wikidata**: [Q74622024](https://www.wikidata.org/wiki/Q74622024)  
**Source**: https://4ort.xyz/entity/jacob-ridder


## References

1. Catalogus Professorum Academiae Groninganae
2. Mathematics Genealogy Project
3. KNAW Past Members
4. Biografisch Portaal