# Third-party data notices

Lessons 0031 onward use or adapt open lexical data from the following projects.

- Simple English Wiktionary, extracted by Kaikki/Wiktextract: CC BY-SA 4.0 and GFDL.
- ECDICT: MIT License.
- Princeton WordNet 3.0: Princeton WordNet License.
- CMUdict: Carnegie Mellon University license.
- Pyphen US English hyphenation patterns: see `LICENSES/HYPHEN-EN-US-NOTICE.txt`.

The corresponding notices are stored in the `LICENSES` directory.