East, Roger, author
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Melady, Thomas Patrick, author
Macmillan, 1961
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North Corolina : The American Biographical Institute, 1986,
Buku Referensi
Ople, Blas F., author
The Institute for Public Policy, 2001
Buku Teks
edited by Frank E. Bair
Gale Research Inc., 1991
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