Wiarda, Howard J., author
Westview Press, 1992
Buku Teks
Sage Publications, 1987
Buku Teks
Hanke, Lewis
D. Van Nostrand Company, 1959
Buku Teks
Keegan, William F., author
Oxford University Press, 2017
eBooks
Christie, Agatha, 1890-1976, author
Gramedia Pustaka Utama, 2018
Buku Teks