Peter Buchholz (1968) Perspectives for Historical Research in Germanic Religion, History of Religions, vol. 8, no. 2, 111-138.
Richard North, Pagan words and Christian meanings (Cambridge, Univ., Diss., 1987, sebuah studi tentang konsep pra-Kristen Jermanik terhadap pikiran dan jiwa, dan tentang reinterpretasi Kristen terhadap paganisme), Rodopi, 1991, ISBN 978-90-5183-305-8.