Wheeler, Geoffrey
Bodley Head, 1966
Buku Teks
Stephen Young [and others]
Prentice-Hall, [date of publication not identified]
Buku Teks
Artikel Jurnal
Morrison, Alastair M., author
Delmar, 1996
Buku Teks
Middleton, Victor T.C., author
Butterworth-Heinemann, 2000
Buku Teks