# Baltimore county

> 1929 publication by Maryland Geological Survey

**Wikidata**: [Q51445299](https://www.wikidata.org/wiki/Q51445299)  
**Source**: https://4ort.xyz/entity/baltimore-county-q51445299


## References

1. Biodiversity Heritage Library
2. [Library of Congress Online Catalog](https://lccn.loc.gov/gs30000244)
3. WorldCat
4. Internet Archive
5. [Open Library](https://openlibrary.org/books/OL253038M.json)
6. HathiTrust Catalogue
7. British Library online catalogue
8. [Source](https://opac.uni-erfurt.de/DB=1/XMLPRS=N/PPN?PPN=472484168)