Meier, Gerald M.
Oxford University Press, 1984
Buku Teks
Nafziger, E. Wayne
Cambridge University Press, 2006
Buku Teks
Handelman, Howard
Pearson/Prentice Hall, 2006
Buku Teks
Lewis, William Arthur, 1915-
University of Ghana by the Ghana Pub, 1971
Buku Teks
Todaro, Michael P.
Longman, 1997
Buku Teks