Collins, Mark J.
Springer, 2012
eBooks
Irwin, Keith Gordon
homas Y. Crowell, 1963
Buku Teks
Laurel Saville, Steve Gordhan, Jodhua Berger, Sarch Dougher, editor
Page one publishing pte ltd, 2011
Buku Referensi
Skarmeta, Antonio
Akubaca, 2002
Buku Teks
Jang, Hyong-hwi
Doseo, 2007
Buku Teks