Silver_Ingot References
2. Williams, Gareth. "BBC - History - Ancient History in depth: Viking Money." BBC News. February 17, 2011. Accessed April 26, 2017. http://www.bbc.co.uk/history/ancient/vikings/money_01.shtml.
3. Kershaw, Jane. "Viking Metal." The problem of Viking silver ingots. January 01, 1970. Accessed April 26, 2017. http://vikingmetalwork.blogspot.com/2013/04/the-problem-of-viking-silver-ingots.html.