Johnson, Carol
Allen and Unwin, 1989
Buku Teks SO
Bailey, Cyril
Oxford University Press, 1951
Buku Teks SO
edited by Val Moses
Grayson Publishing, 2007
Buku Teks SO
Zainah Anwar
Yayasan Mohamed Noah; Petaling Jaya, Selangor, Malaysia , 2011
Buku Referensi
Klaveness, Jan O`Donnell
Macmillan, 1983
Buku Teks SO