McGraw-Hill, 1968
Buku Referensi
Wares, Alan C., author
Santa Ana, 1968
Buku Teks
Easthope, Antony, editor
Routledge , 1991
Buku Teks
Seale, Patrick, author
Yayasan Litera Indonesia, 2000
Buku Teks
planned and supervised by Dan Golenpaul Associates
Simon and Schuster, 1967
Buku Referensi