Angle, Paul M
The Nation Divided
Fawcett Publications,Inc, 1960
Buku Teks
Woodward, Ralph Lee
Central America: a nation divided
Oxford University Press , 1985
Buku Referensi
Olsen, Jack
Silence on monte sole / Jack Olsen
G.P. Putnam's Sons, 1968
Buku Teks
Elliott, J. H.
Europe divided 1559-1598
Collins, 1968
Buku Teks
The end of literary theory / Stein Haugrom Olsen
Cambridge University Press, 1987
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