Lipsey, Richard G., 1928-, author
Weidenfeld and Nicolson, 1972
Buku Teks
Slavin, Stephen, author
Richard D. Irwin, 1991
Buku Teks
Morgan, Theodore, author
Prentice-Hall, 1950
Buku Teks
Cairncross, Alec, author
Butterworth, 1960
Buku Teks
Johnson, Alvin S., author
Hearh & Co., 1911
Buku Teks