Corson, John J.
McGraw-Hill , 1963
Buku Teks
Beck, J. Murray
University of Toronto Press, 1957
Buku Teks
W. Funston, Bernard
Carswell, 1994
Buku Teks
Stedman, Stephen John
Lynne Rienner Publishers, 1991
Buku Teks
Saywell, John J.
University of Toronto Press , 1957
Buku Teks