Hardy, R.H
Oxford University Press, 1987
Buku Teks SO
Stanley M. Zydlo Jr., James A. Hill
Random House, 1990
Buku Teks SO
Doubleday, 1979
Buku Teks SO
Stanway, Andrew
Sheldon Press, 1990, 1990
Buku Referensi
Goth, Peter
A Ward Lock Book, 1994
Buku Referensi