Baum, Warren C., author
Oxford University Press , 1985
Buku Teks
Jayarajah, Carl, author
World Bank, 1996
Buku Teks
Oxford University Press, 1993
Buku Teks
Kiernan, Matthew J., author
American Management Association;, 2009
eBooks
World Bank
World Bank, 1981
Buku Teks