21
by Clark, Colin
Published 1957
22
by Mohamed Ariff, K. A, 1940-
Published 1991
23
by Ashworth, William
Published 1952
24
by Gilbert, Alan, 1944-
Published 1990
25
Published 1983
26
by Moorsom, Richard
Published 1984
27
Published 1941
28
by Bhagawati, Jagdish N, 1934-
Published 1966
29
by Harris, Nigel
Published 1990
30
by Khor, Martin.
Published 2008
31
32
Published 1998
33
34
35
by Caratsch, Claudio
Published 1994
36
37
by Huhtala, Marie T.
Published 2002
38
by Yu, Xintian
Published 2004
39
40
Published 1994