Note 462 — Chapter VI · SORCERY AND OCCULT ARTS.
Reading edition
Olaf Tryggvesson’s Saga, 69, 70, 83 (Laing’s Heimskringla).—Kristinrettr Thorlaks oc Ketils, c. xvi.
For the intimate connection between sorcery and malignant spirits, see Finn Magnusen’s Priscæ Vet. Boreal. Mythologiæ Lexicon, s. v. Tröll, pp. 474 sqq.