Cook, Peter, author
Academy Editions, 1996
Buku Teks
Anderson, Hugh, author
Twayne Publishers, 1968
Buku Teks
Bernard, Marie Fernand, author
Bruxelles, 1951
Buku Teks
Lipsey, Richard G., 1928-, author
Harper Collin, 1996
Buku Teks
Adreson, W. H. Locke, author
Prentice Hall of India, 1986
Buku Teks