21
by Powell
Published 1993
22
by Southern, 1912-
Published 1978
23
Published 1988
24
by Zein
Published 2003
25
by Hunter
Published 1998
26
27
by Al-Attas
Published 2014
28
29
by Forest
Published 2003
30
31
32
33
by Miles
Published 2008
34
35
by Heddendorf
Published 2009
36
37
by Ghazali Basri
Published 1994
38
39
by Blanchard
Published 1993
40
by Potts
Published 1980