# Karl Haefner
**Wikidata**: [Q55895096](https://www.wikidata.org/wiki/Q55895096)  
**Source**: https://4ort.xyz/entity/karl-haefner


## References

1. Integrated Authority File
2. CERL Thesaurus
3. Catalog of the German National Library
4. [Source](http://thesaurus.cerl.org/record/cnp01078052)