# ice age

> period of long-term reduction in temperature of Earth's surface and atmosphere

**Wikidata**: [Q49367](https://www.wikidata.org/wiki/Q49367)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Ice_age)  
**Source**: https://4ort.xyz/entity/ice-age-q49367-2


## References

1. [Source](https://github.com/JohnMarkOckerbloom/ftl/blob/master/data/wikimap)
2. [Nuovo soggettario](https://thes.bncf.firenze.sbn.it/termine.php?id=32656)
3. Nuovo soggettario
4. Freebase Data Dumps. 2013
5. BBC Things
6. YSO-Wikidata mapping project
7. Quora
8. National Library of Israel
9. KBpedia
10. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)