"The Ring Saga". birminghamopera.org.uk. 2013. Archived from the original on 5 March 2016. Retrieved 5 August 2013.
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For a detailed examination of Wagner's sources for the Ring and his treatment of them, see, among other works, Deryck Cooke's unfinished study of the Ring, I Saw the World End (Cooke 2000), and Ernest Newman's Wagner Nights. Also useful is a translation by Stewart Spencer (Wagner's 'Ring of the Nibelung': Companion, edited by Barry Millington) which, as well as containing essays, including one on the source material which provides an English translation of the entire text that strives to remain faithful to the early medieval Stabreim technique Wagner used. Cooke, Deryck (2000). I Saw the World End: A Study of Wagner's Ring. New York: Oxford University Press. ISBN0-19-315318-1.
