Lundgren, Stefan, author
Quintessence publishing, 2008
Buku Teks
Paridah Abd. Samad, author
Affluent Master, 1999
Buku Teks
Macneil, Ian R.
Oxford University Press, 1992
Buku Teks
Durrant, Will
Simon and Schuster, 1957
Buku Teks
Hulme, Edward Maslin
Century Co., 1914
Buku Teks