21
Published 2010
IEEE

22
Published 2006
IEEE

23
Published 1989
IEEE

24
Published 2010
IEEE

25
Published 2010
IEEE

26
Published 2010
IEEE

27
Published 1992
IEEE

28
Published 2007
IEEE

29
Published 2002
IEEE

30
Published 1996
IEEE

31
Published 1999
IEEE

32
Published 2004
IEEE

33
Published 1993
IEEE

34
Published 1995
IEEE

35
Published 1996
IEEE

36
Published 1997
IEEE

37
Published 1998
IEEE

40
Published 2001
IEEE