This paper, focusing on issues of magic and female characters in Tolkien's medieval narrative verse, was presented at the University of Vermont Tolkien Conference on April 11, 2015 and does not take into account Verlyn Flieger’s commentary (especially concerning Galadriel) in her 2016 edited volume The Lay of Aotrou and Itroun.
"Guinevere, Grímhild, and the Corrigan: Witches and Bitches in Tolkien’s Medieval Narrative Verse,"
Journal of Tolkien Research: Vol. 4
, Article 8.
Available at: http://scholar.valpo.edu/journaloftolkienresearch/vol4/iss2/8