I am reminded of this thread by a recent enquiry about Le Roi Renaud, and can now add some further links.
English language verse "translations" of two Swedish sets contained in Afzelius' Svenska Folk-Visor (1814-16), Sir Olof in the Elve Dance (Herr Olof i Elfvornas Dans) and The Elf-Woman and Sir Olof (Elf-Qvinnan och Herr Olof) can be seen at Celtic Folklore:
The Fairy Mythology: illustrative of the Romance and Superstition of Various Countries Thomas Keightley, 1878.
Fortysix (!) variants of the Norwegian version are available at the Norwegian Universities Documentation Project: