De Burgh, W.G. (William George), 1866-1943
Penguin Books, 1953
Buku Teks
Spengler, Oswald, author
Alfred A. Knopp, 1947
Buku Teks
Smith, Preserved, author
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Buku Teks
edited by Joachim Herrmann, Joachim Herrmann and Erik Zurcher
Routledge, 1996
Buku Referensi
edited by S.J. De Leat, A.H. Dani, J.L. Lorenzo and R.B. Nunoo
Routledge , 1994
Buku Referensi