Pye, Keith
Stanley Thornes , 1992
Buku Teks
Jones, Bill
Manchester University Press, 1991
Buku Teks
Jones, Bill
Manchester University Press, 1990
Buku Teks
Jones, Bill
Manchester University Press, 1993
Buku Teks
Beer, Samuel H.
Alfred A. Knopf, 1966
Buku Teks