Readers who wish to compare Green's myths to the original sources should consult The Prose Edda, compiled in the thirteenth century by an Icelander named Snorri Sturluson. The Elder Edda, compiled in the twelfth century, is a collection of poems written from 800 to 1100, and a good source of Norse myths. The Nibelungenlied (c. 1200) tells the story of Sigmund, Sigurd, and Brynhild in a much expanded version and would be an ambitious reading project.

The Norse sagas, available in excellent translations by Magnus Magnusson and Herman Palsson, are excellent reading for those already familiar with Norse mythology.

The Namia books of C. S. Lewis and The Lord of the Rings by J. R. R. Tolkien are both heavily influenced by Norse myth, and German composer Richard Wagner (1813-1883) used the Norse myths as the basis for his series of operas, The Ring of the Nibelung (1876).