"James Tennant". The Mineralogical Record. Archived from the original on 20 July 2011. Retrieved 22 July 2011.
"James Sowerby (1757-1822)". The Mineralogical Record Museum of Art. Mineralogical Record Inc. Archived from the original on 20 July 2011. Retrieved 21 November 2007.
"James Tennant". The Mineralogical Record. Archived from the original on 20 July 2011. Retrieved 22 July 2011.
"James Sowerby (1757-1822)". The Mineralogical Record Museum of Art. Mineralogical Record Inc. Archived from the original on 20 July 2011. Retrieved 21 November 2007.