Daugherty, Carroll R.
Houghton Miffiln, 1950
Buku Teks
Wicksteed, Philip Henry, 1844-1927, author
Augus M. Kelley, 1950
Buku Teks
Mill, John Stuart
Colonial Press, 1898
Buku Klasik
Little, Ian M.D.
The Clarendon Press, 1957
Buku Teks
Bastiat, Frederick
D. Van Nostrand , 1964
Buku Klasik