Lewis, H. D. (1969). The elusive mind: Based on the first series of the Gifford lectures delivered in the University of Edinburgh, 1966-68. Allen & Unwin.
Lua i Stíl Chicago (17ú heag.)Lewis, Hywel David. The Elusive Mind: Based on the First Series of the Gifford Lectures Delivered in the University of Edinburgh, 1966-68. London: Allen & Unwin, 1969.
Lua MLA (9ú heag.)Lewis, Hywel David. The Elusive Mind: Based on the First Series of the Gifford Lectures Delivered in the University of Edinburgh, 1966-68. Allen & Unwin, 1969.
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