Todaro, Michael P.
Longman, 1992
Buku Teks
Handelman, Howard
Pearson/Prentice Hall, 2006
Buku Teks
edited by P. Ebow Bondzi-Simpson
Praeger, 1992
Buku Teks
Afsghar, Haleh
Longman, 1991
Buku Teks
ed. by József Nyilas ; translation by István Véges
Sijthoff, 1977
Buku Teks