Scmidt-Bleek, F
Tenn. Center for Business and Economic Research University of Tennessee, 1972
Buku Teks
The Johns Hopkins University Press , 1972
Buku Teks
Pritchett, C. Herman, author
University of North California Press, 1943
Buku Teks
Boxill, Roger, author
Macmillan, 1994
Buku Teks
Todaro, Michael P., author
Longman, 1989
Buku Teks