Williams & Wilkins , 1991
Buku Teks
Blackwell Scientific , 1987
Buku Teks
by Rob Ranyard [and others]; edited by Rob Ranyard, W. Ray Crozier and Ola Svenson
Routledge , 1997
Buku Teks
Spriger-Verlag, 1993
Buku Teks
International Monetary Fund , 1994
Buku Teks