Francis, G. G. (1881). The smelting of copper in the Swansea district of South Wales: From the time of Elizabeth to the present day (2d ed.). H. Sotheran & co..
Chicago-referens (17:e uppl.)Francis, George Grant. The Smelting of Copper in the Swansea District of South Wales: From the Time of Elizabeth to the Present Day. 2d ed. London and Manchester: H. Sotheran & co., 1881.
MLA-referens (8:e uppl.)Francis, George Grant. The Smelting of Copper in the Swansea District of South Wales: From the Time of Elizabeth to the Present Day. 2d ed. H. Sotheran & co., 1881.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.