edited by Richard Haigh, Dai Harris
Routledge, 1994
Buku Teks
Pritchard, John, author
Viking, 1992
Buku Referensi
general editor Michael Renshall
Butterworth, 1990
Buku Referensi
Carvan, John, author
LBC Information Services, 1997
Buku Teks
Carvan, John, author
LBC Information Services Holmes Beach, 1997
Buku Teks