Hazard, Harry W., author
Princeton University Press, 1951
Buku Referensi
Robinson, Francis, author
Facts on File, 1982
Buku Referensi
Roolvink, R., author
Djambatan, 1957
Buku Referensi
edited by Edward Whiting Fox
Oxford University Press, 1957
Buku Teks
Sellman, Roger Raymond, author
Edward Arnold, 1954
Buku Referensi