Palmer, E.H.
Routledge & Kegan Paul, 1956
Buku Referensi
Wehr, Hans, 1909-1981
Spoken Language Services, 1976
Buku Referensi
Lanyon-Orgill, Peter A.
Luzac & Co., 1944
Buku Referensi
Boyle, John Andrew
Luzac & Company, 1949
Buku Referensi
Yuen, Ren Chao
Harvard University Press, 1962
Buku Referensi