personal link Postat per Govanus a 2 de junh 2015 en English https://www.groundstability.com/public/web/home.jspx
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Comentari de Govanus lo 2 de junh 2015 a 19:28
https://www.gov.uk/coal-mining-records-data-deeds-and-documents#historic-data
Comentari de Govanus lo 2 de junh 2015 a 19:29
https://www.gov.uk/government/publications/con29m-coal-and-brine-area-polygon-data
Comentari de Govanus lo 2 de junh 2015 a 19:52
https://www.gov.uk/government/publications/ngec-regional-prime-maps