Gerald Segal
Simon and Schuster, 1996
Buku Referensi
Allen L. Hammond [and others]
Oxford University Press , 1996
Buku Teks
Mansbach, Richard W., author
Houghton Miffiln, 2000
Buku Teks
Cleaver, Tony, author
Routledge, 1997
Buku Teks
Payne, Richard J., 1949-, author
Pearson Education , 2014
Buku Teks