edited by Martina Duttman and Felix Zwoch
birkha'user Verlag, 1998
Buku Teks SO
Karch, Amy M.
Lippincott Williams & Wilkins, 2001
Buku Teks
Buchanan, Peter
Phaidon Press, 1995
Buku Teks SO
Funk & Wagnalls, 2000,
Buku Referensi
Reid, D.A.G.
London: Longman, 1966
Buku Teks