Berlin Hodder and Stoughton 1966
Buku Referensi
London, London Longmans
Buku Referensi
Wichman, Karl, author
Philadelphia, David McKay Company, 1944
Buku Referensi
London; Cassell LTD., 1978
Buku Referensi
editor, John DeFrancis
Allen & Unwin, 1997
Buku Referensi