Maritain, Jacques
Man and the state
The University of Chicago Press, 1951
 Buku Teks SO
Lindsay, A.D.
The modern democratic state
Oxford University Press, 1959
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Laski, Harold J.
Liberty in the modern state
George Allen and Unwin, 1948
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Laski, Harold J.
Liberty in the modern state
Penguin Books, 1937
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Strong, C.F.
Modern political constitutions: an introduction to the comparative study of their history and existing forms
Sidgwick & Jackson Limited, 1960
 Buku Teks SO