Buchanan, James M., author
Liberty Fund, 2001
Buku Referensi
Buchanan, James M., author
Liberty Fund, Inc., 2001
Buku Referensi
Buchanan, James M., author
Liberty Fund, 2002
Buku Referensi
Frohlich, Norman
Prentice-Hall, 1987
Buku Teks
Stokes, Susan Carol, author
Cambridge University Press, 2014
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