Ward, A.C.
The English Language Book, 1928
Buku Teks
J.L. Granatstein ...[et al.]
McGraw-Hill Ryerson, 1983
Buku Teks
Ewen, David, author
Prentice Hall, 1968
Buku Referensi
Kim, Young-na, author
Laurence King Publishin, 2005
Buku Teks
Haftman, Werner, author
Frederick A. Praeger, Pub., 1960
Buku Referensi