Bhaduri, Amit
London Academic Press , 1983
Buku Teks
edited by Carl Eicher and Lawrence Witt
McGraw-Hill , 1964
Buku Teks
edited by Clifton R. Wharton
Aldine Publishig, 1969
Buku Teks
Schultz, Theodore W., author
McGraw-Hill, 1953
Buku Teks
Mosher, Arthur T., author
Agricultural Development Council , 1969
Buku Teks