# copyleft

> technique in copyright law of granting freedoms over copies of a work, and over derivative works by using a share-alike provision

**Wikidata**: [Q133475](https://www.wikidata.org/wiki/Q133475)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Copyleft)  
**Source**: https://4ort.xyz/entity/copyleft


## References

1. [Source](https://lingualibre.org/wiki/Q810271)
2. Freebase Data Dumps. 2013
3. [Source](https://www.gnu.org/licenses/copyleft.en.html)
4. [Source](http://data.loterre.fr/ark:/67375/TSO-W04D2X5B-N)
5. BabelNet
6. Wikibase TDKIV