Raju, Jaya, author
Chandos, 2006
Buku Teks
Gleason, Henry Allan
Holt, Rinehard, 1963
Buku Teks
Slaby, Steve M., author
John Wiley & Sons, 1976
Buku Teks
Pressat, Roland, author
Methuen, 1966
Buku Teks
Hekman, Susan J., author
Polity Press, 2014
Buku Teks