Possible Clues:

• 800-year-old work on mythology
• Early Icelandic literary work
• Put an E back on it for the Norse
• Is it the turn of the fatherly editor put on another E in Norse?
• The wrong way to put E on for the Norse
• English divine given a set of Old N orse poems
• Ancient Icelandic work
• A parental class of an editor? That's a long story
• Classical collection
• Books produced by journalist and lawyer