1
by Fox
Published 2003
2
by Tarpinian
Published 1996
3
Published 1992
4
Published 2006
5
by Dr. A. K. Srivastava
Published 2006
6
by Dr. A. K. Srivastava
Published 2006
7
by Dr. A. K. Srivastava
Published 2006
8
by Thomas
Published 2007
9
by Montgomery
Published 2009
10
by Jain, D.
Published 2005
11
by Verrier
Published 2004
12
by Lerwill
Published 2013
13
Published 2005
14
by Thomas
Published 2005
15
by Lucero
Published 2012
16
by Thomas
Published 1994
17
by Counsilman
Published 1997
18
by Elkington
Published 1980
19
by Colwin
Published 1977
20
Published 1978