5Bett, H. & Johannes, 1964, Scottus Eriugena, A Study in Medieval Philosophy, New York, Russell & Russell.
6Caputo, 1974, "Meister Eckhart and the later Heidegger: the mystical element in Heidegger's thought", part one, in the Journal of the History of Philosophy 12 (4).
7Copleston, F. , 1993, A History of Philosophy, vol. 2, in Medieval Philosophy, Image Books Doubleday, New York.
8Erivgenae, 1968, Periphyseon (De Divisione Naturae ), Scriptores Latini Hiberniae, ed. by I. P. S. Williams, with the collaboration of K Bieler, Dublin: the Dublin Institute for Advanced Studies.
9Kretzamn, N. (ed.), 1982, The Cambridge History of Later Medieval Philosophy, Cambridge.
10Lanzetta, 1992, "Three categories of nothingness in Eckhart", in the Journal of Religion 72 (2).