* Jean van Heijenoort, 1967, From Frege to Gödel: A Source Book in Mathematical Logic, Harvard University Press, Cambridge, MA, ISBN 0-674-32449-8 ( pbk.
* Jean van Heijenoort, 1967, From Frege to Gödel: A Source Book in Mathematical Logic, 1879-1931, 3rd printing 1976, Harvard University Press, Cambridge, MA, ISBN 0-674-32449-8.
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