Lewis, Norman
New York Harper and Row 1963
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Wichman, K., author
New York, David Mckay Company
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Barnhart, Clarence
Garden City, New York, Doubleday, 1967
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Breul, Karl, author
Boston D.C. Heath 1936
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Fowler, H. W. (Henry Watson), 1858-1933, author
New York Oxford University Press 1965
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