# Johann Haßler
**Wikidata**: [Q102254899](https://www.wikidata.org/wiki/Q102254899)  
**Source**: https://4ort.xyz/entity/johann-ha-ler


## References

1. Staatsarchiv Sigmaringen
2. Catalog of the German National Library
3. Alleged member of einzatskommando
4. Integrated Authority File