Palmer, Alan
Penguin Books, Harmondsworth, Middlesex, 1981
Buku Teks SO
Cohen, John Michael, 1903-1989
Penguin Books, 1971
Buku Referensi
Cohen, John Michael, 1903-1989
Allen Lane, 1980
Buku Referensi
E.C. Young
Allen Lane, 1979
Buku Referensi
general editor: Laurie Hergenhan ; editors : Bruce Bennett ... [et al.]
Penguin Books, 1988
Buku Teks