21
Published 2003
IEEE

22
Published 2004
IEEE

23
Published 2005
IEEE

24
Published 2006
IEEE

25
Published 2007
IEEE

26
Published 2008
IEEE

27
Published 2009
IEEE

28
Published 2008
IEEE

29
Published 2010
IEEE

30
Published 1988
IET

31
Published 1979
IEEE

32
Published 2010
IEEE

33
Published 2011
IEEE

34
Published 1982
IEEE

35
Published 1983
IEEE

36
Published 1984
IEEE

37
Published 1985
IEEE

38
Published 1986
IEEE

39
Published 1988
IEEE

40
Published 1989
IEEE