by Stewart Sutherland ... [and others]
Routledge, 1988
Buku Teks SO
edited by Stewart Sutherland, Leslie Houlden, Peter Clarke, Friedhelm Hardy
Routledge, 1988
Buku Referensi
Fryer, D.W.
McGraw-Hill, 1965
Buku Teks SO
by International Monetary Fund
International Monetary Fund, 1999
Buku Teks SO
Schultz, Theodore W.
The Minchigan of Univ. Press, 1966
Buku Teks