Swerdlow, Irving, author
Frederick A. Praeger, 1975
Buku Teks
Gant, George F., author
University of Wisconsin Press, 1979
Buku Teks
Todaro, Michael P., author
Addison-Wesley , 2000
Buku Teks
Todaro, Michael P., author
Longman, 1997
Buku Teks
Todaro, Michael P., author
Addison-Wesley , 2000
Buku Teks