Griffin, Keith, author
St. Martin Press, 1989
Buku Teks
Meier, Gerald M., author
Oxford University Press, 1984
Buku Teks
Nafziger, E. Wayne, author
Cambridge University Press, 2006
Buku Teks
Handelman, Howard, author
Pearson/Prentice Hall, 2006
Buku Teks
Lewis, William Arthur, 1915-, author
University of Ghana by the Ghana Pub, 1971
Buku Teks