Allen, Martin (2001). "The Volume of the English Currency, 1158–1470". The Economic History Review. 54 (4): 595. doi:10.1111/1468-0289.00204. JSTOR3091623.
Allen, Martin (2001). "The Volume of the English Currency, 1158–1470". The Economic History Review. 54 (4): 595. doi:10.1111/1468-0289.00204. JSTOR3091623.