Witzke, "Richard Wagner's Der Ring des Nibelungen: Another Look," Christian Scholar's Review, 2021

A peer reviewed article in Christian Scholar's Review examining how Wagner built the Ring from the Nibelungenlied, the Volsunga Saga and the Icelandic Eddas, then transformed that material through Greek dramatic models, by the article's own account patterned after the Oresteia trilogy, to carry philosophical and theological concerns largely absent from the original sources. Its strength is that it is genuinely peer reviewed academic scholarship on exactly this question, source fidelity and adaptation. Its limit is that its own interest is theological and philosophical rather than a specialist study in Old Norse religion, so it is cited here for the sourced fact of the cycle's composite textual basis and its transformation rather than as a comprehensive account of Norse belief.