Hackworth, Green Haywood, author
Government Printing Office, 1940
Buku Teks
Toth, A. G., author
Clarendon Press, 1990
Buku Referensi
McNair, Lord, author
At The University Press, 1956
Buku Teks
Hayek, F.A
Routledge & Kegan Paul, 1973
Buku Teks
edited by Robert J. Janosik
Charles Scribner`s Sons, 1987
Buku Referensi