Todaro, Michael P., author
Addison-Wesley, 2003
Buku Teks
Packard, Philip C., author
Mouton, 1972
Buku Teks
Todaro, Michael P., author
Erlangga, 1998
Buku Teks
edited by M.A. Bienefeld and Martin Godfrey
John Wiley & Sons, 1982
Buku Teks
Bulajic, Milan, author
Martinus Nijhoff, 1993
Buku Teks