1
Published 1993
2
Published 1994
3
Published 2000
4
Published 1988
5
Published 1996
6
7
Published 1991
8
Published 2004
9
Published 1989
10
Published 1989
11
Published 1990
12
Published 1991
13
Published 1992
14
15
16
Published 1989
17
Published 1993
18
Published 1991
19
20
by Esty, Daniel C.
Published 1994