# Johann Hagen
**Wikidata**: [Q55194139](https://www.wikidata.org/wiki/Q55194139)  
**Source**: https://4ort.xyz/entity/johann-hagen


## References

1. Deutsche Biographie
2. Catalog of the German National Library
3. Biographical Dictionary of the History of the Czech Lands
4. Czech National Authority Database
5. Virtual International Authority File