edited by Carl Eicher and Lawrence Witt
McGraw-Hill , 1964
Buku Teks
edited by Clifton R. Wharton
Aldine Publishig, 1969
Buku Teks
Fryer, D.W.
McGraw-Hill, 1965
Buku Teks
World Bank
Oxford University Press, 1991
Buku Teks
Todaro, Michael P.
Longman, 1989
Buku Teks