edited by Carl Eicher and Lawrence Witt
McGraw-Hill , 1964
Buku Teks
Schultz, Theodore W.
McGraw-Hill, 1953
Buku Teks
edited by Clifton R. Wharton
Aldine Publishig, 1969
Buku Teks
edited by Kazushi Ohkawa, Bruce F. Johnston and Hiromitsu Kaneda
University of Tokyo Press, 1969
Buku Teks
Mosher, Arthur T.
Agricultural Development Council , 1969
Buku Teks