Currie, Sir George
Research Organization, 1966
Buku Teks
Crisp, L. F. (Leslie Finlay), author
Yale University Press, 1949
Buku Teks
The University of Michigan, 1976
Buku Teks
Sansom, Katharine, 1883-, author
The Diplomatic Press , 1972
Buku Teks
edited by Jeremy Moon and Campbell Sharman
Cambridge University Press, 2003
Buku Teks