London, London Longmans
Buku Referensi
London; Cassell LTD., 1978
Buku Referensi
Wyld, H.C.
Oxford Blackwell 1953
Buku Teks
editor, John DeFrancis
Allen & Unwin, 1997
Buku Referensi
Wessely, J.E., author
Chicago dsb. Pollett Publ. 1946
Buku Referensi