Branca, Patricia
Croom Helm, 1978
Buku Teks SO
Freymond, Jacques
Frederick A. Preager, 1964
Buku Teks
Thomson, David
Longmans, 1962, 1973
Buku Teks SO
edited by Terry Gourvish
Macmillan Education, 1991
Buku Teks SO
Milton-Edwards, Beverly
Routledge, 2005
Buku Teks SO