Cook, Vivian
Edward Arnold, 2001
Buku Teks SO
Littlewood, William
Cambridge University Press, 1994
Buku Teks SO
Littlewood, William
Cambridge University Press, 1998
Buku Teks SO
Lonergan, Jack
Cambridge University Press , 1994
Buku Teks SO
Richards, Jack C.
Cambridge University Press, 1985
Buku Teks SO