American Society of Appraisers (ASA)

• National Mining Museum Scotland
• National Slate Museum
• Modern History Sourcebook: Women Miners in the English Coal Pits
• Yorkshire Dales Mining Museum
• Langton Matravers Museum
• Peak District Mines Historical Society (PDMHS)
• Cleveland Ironstone Mining Museum
• Sygun Copper Mine
• Blue Hills Tin Streams
• National Coal Mining Museum
• The Museum of Lead Mining
• Honister Slate Mine