(en) Folarin Shyllon, « The Nigerian and African Experience in Looting and Trafficking in Cultural Objects », dans Barbara T. Hoffman (directrice), Art and Cultural Heritage : Law, Policy, and Practice, Cambridge, Cambridge University Press, , 562 p. (ISBN0521857643 et 9780521857642, lire en ligne), p. 138.
(en) Robert Sydney Smith, Kingdoms of the Yoruba, Madison (Wisconsin), University of Wisconsin Press, , 3e éd., 174 p. (ISBN0-299-11604-2, lire en ligne), p. 25.
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« German Discovers Atlantis in Africa; Leo Frobenius Says Find of Bronze Poseidon Fixes Lost Continent's Place », The New York Times, (lire en ligne, consulté le ).