# Klein bottle

> type of non-orientable surface

**Wikidata**: [Q23638](https://www.wikidata.org/wiki/Q23638)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Klein_bottle)  
**Source**: https://4ort.xyz/entity/klein-bottle


## References

1. Freebase Data Dumps. 2013
2. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)