Jansen, Marius B., author
Rand Mc.Nally College Publishing , 1975
Buku Teks
Newman, Robert P.
Macmillan, 1961
Buku Teks
edited by Carla P. Freeman
Palgrave Macmillan, 2015
Buku Teks
Department of State, 1949
Buku Teks
Gupta, Sisir
Asia Publishing House, 1966
Buku Teks