Fisher, H.A.L.
Eyre and Spottiswoode , 1935
Buku Teks
Hebert, Jacques, author
Optimum Publishing International, 1986
Buku Teks
Schlesinger, Arthur M., author
A Marner Book, 2003
Buku Teks
A DK Publishing, 2001
Buku Teks
Burris, Jon, author
Foreign Languages Press, 2010
Buku Referensi