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Monthly Riview Press, 1977
Buku Teks
Sage Publications, Inc, 2005
Majalah, Jurnal, Buletin
Tawney, R.H.
A Mentor Book, 1926
Buku Teks
M. Furqon I. Hanief
Artikel Jurnal
Green, Constance McLaughlin, 1897-1975
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Buku Teks