Notes cf. Charles Simonyi on EDGE quoting Richard Feynman
 cf. D. Guedj: Nicholas Bourbaki, collective mathematician, an interview with Claude Chevalley, The Mathematical Intelligencer vol. 7, no. 2, 1985.  Cf. the two anthologies Philosophy of Mathematics: selected readings edited by P. Benacerraff and H.Putnam, Cambridge University press 1964 and reprinted with some deletions 1985, and J. van Heijenoort's From Frege to Gšdel; a source book in mathematical logic 1879-1931 Harvard University Press 1971.
 In a fine essay, entitled "Bemerkungen zu zwei wenig beachteten 'Gedanken' Pascals" ("Remarks on two of Pascal's 'thoughts' that have hitherto received little attention") in his collection Ausgewþhlte Vortrþge und Aufsþtze (selected talks and essays), Bern 1955 pp. 226-234, the Swiss psychoanalyst and phenomenologist Ludwig Binswanger elaborates on Pascal's "pensŽes" (thoughts or reflections) on this topic and substantiates them with clinical experiences pertaining especially to the role played by symmetries in Rorschach tests.
 cf. chapter III of my Gšdel's Theorems; a Workbook on Formalization, Teubner Texte zur Mathematik, Stuttgart-Leipzig 1991.
 Modular elliptic curves and Fermat's Last Theorem, Ann. Math. 141, 1995, 443 551.
 †ber formal unentscheidbare Sþtze der Principia Mathematica und verwandter Systeme Monatshefte fŸr Mathematik und Physik 37, 1931,173-198. For a translation see Kurt Gšdel, Collected Works, Volume 1, ed. S. Feferman et al, Oxford U. Press 1986.
 cf. p. 39 ff. of the excellent and very readable monograph Undecidable Theories by Tarski, Mostowski and Robinson, North Holland Press 1953.
 cf. the collected works cited before.