Keenleyside, Anne
W. Ross MacDonald School Resource Services Library, 2015
Buku Teks
Alland, Alexander
John Wiley & Sons,Inc., 1980
Buku Teks SO
Firth, Raymond
The New American Library, 1958
Buku Teks SO
Fuentes, Agustin
McGraw-Hill, 2012
Buku Teks
Beals, Ralph L.
Macmillan, 1959
Buku Teks