Bernhard, H. J. (1956). Wonders of the world. New York: Simon and Schuster.
Παραπομπή Chicago StyleBernhard, Hubert J. Wonders of the World. New York: Simon and Schuster, 1956.
MLA CitationBernhard, Hubert J. Wonders of the World. New York: Simon and Schuster, 1956.
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