Mackenzie, W.J.M
Penguin books, 1978
Buku Teks
Mackenzie, W.J.M
Penguin books, 1978
Buku Teks
Lipson, Leslie, author
Prentice-Hall, 1965
Buku Teks
Rush, Michael, author
Harvester Wheatsheaf, 1992
Buku Teks
De Blij, Harm J., author
John Wiley & Sons, 1967
Buku Teks