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2. Keosian, J.: On the Origin of Life, Science, Vol. 131, 479–482, Feb. 19, 1960.
3. Hoyle, F.: The Nature of the Universe. Harper & Bros., New York, 1950.
4. Suzuki, D. T.: The Zen Doctrine of No-Mind, Rider & Co., London, 1949.
5. Hutchinson, E. C.: How to Think Creatively, Abingdon-Cokesbury Press, New York, 1949.