C.S. Hammond , 1961
Buku Referensi
C.S. Hammond & Co. , 1960
Buku Referensi
Garden City Books, [date of publication not identified]
Buku Referensi
James E Davis, colsultan
Graphic Learning,, 1978
Buku Referensi
Wiegand, Patrick
Oxford University Press, 1994
Buku Teks