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http://en.wikipedia.org/wiki/Paul_Langevin
(last accessed October 21, 2009).
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http://en.wikipedia.org/wiki/Paul_painleve
(last accessed October 21, 2009).
3. Au, W. W. L. (1993) The Sonar of Dolphins, Springer, New York.
4. Bell, T. G. (1962) Sonar and Submarine Detection, U.S. Navy Underwater Sound Lab. Rep. 545.
5. Belloc, M. G. (1929a) La Croisière de la Tanche en Août 1927, Rapports et Procès-verbaux des Réunions, Conseil P, 55, 139–150 [in French].