# Matthijs Johannes Janssen
**Wikidata**: [Q21546526](https://www.wikidata.org/wiki/Q21546526)  
**Source**: https://4ort.xyz/entity/matthijs-johannes-janssen


## References

1. [Catalogus Professorum Academiae Groninganae](http://hoogleraren.ub.rug.nl/?page=showPerson&type=hoogleraar&hoogleraar_id=160)
2. Catalogus Professorum Academiae Groninganae
3. Virtual International Authority File
4. National Library of Israel Names and Subjects Authority File