# Karl Helbing
**Wikidata**: [Q94928615](https://www.wikidata.org/wiki/Q94928615)  
**Source**: https://4ort.xyz/entity/karl-helbing


## References

1. Catalog of the German National Library
2. archINFORM
3. [archINFORM](https://www.archinform.net/service/wd_aiarch.php)