Seckler-Hudson, Catheryn, author
Washington, D.C., The American University Press
Buku Teks
written by M. C. Barnes [and others]
Allen & Unwin, 1970
Buku Teks
Hatch, Mary Jo
Oxford University Press, 1997
Buku Teks
Pugh, D. S.
Buku Teks
Litterer, Joseph August, 1926-, author
John Wiley & Sons, 1973
Buku Teks