1C H Kahn, Retrospect on the Verb 'to be'and Concept of Being, S. Knuuttila and Hlntikka ed, The Logic of Being, D Reidel Publishing Company, Dordrecht - Holland, 1986,p. 21; of Preface, Ⅸ.
2C H Kahn, Retrospect on the Verb 'to be' and Concept of Being[J].
3C H Kahn, The Verb'be' in Ancient Greek[M]. D Reidel Publishing Company, 1973.
4C J De Vogel, Rethinking Plato and Platonism[M]. E J , Brill, Leiden, 1988.
5G Vlastos, Degree of Reality in Plato[M]. N D Smith, ed, Plato Critical Assessments, vol. Ⅱ, Routledge,New York, 1998.
