Hibberd, James Shirley, author
Groombridge, 1953
Buku Teks
Bremness, Lesley, author
Dorling Kindersley, 1988
Buku Teks
Barnard, Julian, author
Ashgrove Press, 1988
Buku Referensi
Harvey, Clare G., author
Thorsons, 1995
Buku Referensi
Diekelmann, John, author
New York: McGraw-Hill, 1982
Buku Teks