# gravel

> mix of crumbled stone (grain size range between 2 – 63 mm according to ISO 14688)

**Wikidata**: [Q133833](https://www.wikidata.org/wiki/Q133833)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Gravel)  
**Source**: https://4ort.xyz/entity/gravel


## References

1. AGROVOC
2. Integrated Authority File
3. National Agricultural Library Thesaurus
4. [Nuovo soggettario](https://thes.bncf.firenze.sbn.it/termine.php?id=62566)
5. datos.bne.es
6. Library of Congress Authorities
7. Global Agricultural Concept Space
8. BabelNet
9. [Environment Ontology](https://raw.githubusercontent.com/INCATools/environments2wikidata/master/matches/curated-high-confidence-envo.tsv)
10. Quora
11. General Finnish Ontology
12. National Library of Israel
13. KBpedia