Aubrey, Henry G., author
Frederick A. Praeger, 1964
Buku Teks
Fellner, William, 1905-, author
Princeton University Press, 1966
Buku Teks
Humphrey, Thomas M.
Praeger Studies , 1982
Buku Teks
Caves, Richard E., author
Harper Collins College Publishers, 1996
Buku Teks
International Labour Office,, 1966
Buku Teks