Lucas, John, author
Cassell, 1980
Buku Referensi
Krever, Richard.
Butterworth, 1986
Buku Teks
Kinyon, Stanley V.
West Publishing Company, 1971
Buku Teks
Grimes, Ellen, author
McGraw-Hill, 1978
Buku Teks
Jones, Barry
The M E Handbook Series, 1991
Buku Teks