Keegan, John, author
Routledge, 1996
Buku Referensi
Hicks, John R., author
Houghton Mifflin , 1946
Buku Teks
Anderson, Bonnie S.
Harper Perennial, 1988
Buku Teks
Souliw, Charles Georges, author
J. Cape & H. Smith, 1931
Buku Teks
Emerling, Jae, author
Routledge , 2012
Buku Teks