Littlewood, William T.
Cambridge University Press, 1994
Buku Teks SO
Mitchell, Rosamond
Routledge, 2004
Buku Teks SO
Mitchell, Rosamond
Arnold, 1998
Buku Teks SO
editedby Barbara Kroll
Cambridge University Press, 1990
Buku Teks SO
Allen, Edward David, 1923-
Harcourt Brace Jovanovich, c1977
Buku Teks SO