21
by Beer, Michael.
Published 1988
22
by Alexander, Roy.
Published 1989
23
by Buskirk, Richard H.
Published 1992
24
by Boland, Daniel M.
Published 1993
25
by Good, Bill.
Published 1991
26
by Zhu, Xiao Jie
Published 2008
27
by Tack, Alfred.
Published 1993
28
29
by Schuller, Gary.
Published 1989
30
31
32
33
by Elliott, Kevin
Published 2004
34
by Manning, Gerald L.
Published 1992
35
by Carnegie, Dale
Published 2003
36
by Rogen, Arthur.
Published 1991
37
by Dawson, Roger
Published 2004
38
by Ho, Oliver Y.Y.
Published 1997
39
by Harvey, Christine.
Published 1991
40
by Shoop, Fiona
Published 2004