Coffey, Peter, author
Macmillan, 1971
Buku Teks
edited by Robert Z. Aliber
Macmillan, 1977
Buku Teks
Johnson, Harry G., author
Harvard University Press , 1967
Buku Teks
Halm, George N., author
University of North-Carolina Press, 1945
Buku Teks
Coffey, Peter, author
Macmillan, 1974
Buku Teks