Collins 2002, str. 228. Collins, Billie Jean (2002), »Necromancy, Fertility and the Dark Earth: The Use of Ritual Pits in Hittite Cult«, v Mirecki, Paul; Meyer, Marvin (ur.), Magic and Ritual in the Ancient World, Leiden, The Netherlands: Brill, str. 224–233, ISBN90-04-10406-2