Christensen, Kit R.
McGraw-Hill, 2002
Buku Teks
edited by Mary Cherian and Rosalind Y. Mau
McGrow-Hill, , 2003
Buku Teks
Planet, Lonely
Lonely Planet, 2012
Buku Teks
Harvey, Clare G.
Thorsons, 1995
Buku Referensi
Wagstaff, Liz
Quadrille, 1999
Buku Referensi