“Nordic Witchcraft in Transition: Impotence, Heresy, and Diabolism in 14th-century Bergen”, Scandia. Tidskrift för historisk forskning, vol. 63, no. 1, p. 17-33, 1997.

“Anaphrodisiac Charms in the Nordic Middle Ages: Impotence, Infertility, and Magic”, Norveg. The Norwegian Journal of Folklore, vol. 38, p. 19-42, 1998.

Witchcraft and Magic in the Nordic Middle Ages. Philadelphia: University of Pennsylvania Press, 2011. Website