Champion, Walter T, author
WEST , 2009
Buku Teks
Pearson, Michael W., author
Pearson education, 2015
Buku Teks
Bigelow, Robert P., author
Upper Saddle River, NJ: Prentice Hall, 1975,
Buku Referensi
Jackson, Grdon E., author
Prentice-Hall, 1993
Buku Referensi
Juergensmeyer, Julian Conrad, author
Little, Brown, 1982
Buku Teks