Letwin, S. R. (1998). The pursuit of certainty: David Hume, Jeremy Bentham, John Stuart Mill, Beatrice Webb. Liberty Fund.
Chicago-čujuhus (17. p.)Letwin, Shirley Robin. The Pursuit of Certainty: David Hume, Jeremy Bentham, John Stuart Mill, Beatrice Webb. Indianapolis: Liberty Fund, 1998.
MLA-čujuhus (9. p.)Letwin, Shirley Robin. The Pursuit of Certainty: David Hume, Jeremy Bentham, John Stuart Mill, Beatrice Webb. Liberty Fund, 1998.
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