@ARTICLE{ey1,
  AUTHOR	    = {A. AAA and B. BBB and A. CCC and E. EEE},
  TITLE       = {Title1},
  YEAR        = {1968}
}

@ARTICLE{ey1a,
  AUTHOR	    = {A. AAA and B. BBB and A. CCC and E. EEE},
  TITLE       = {Title1},
  YEAR        = {1969}
}

@ARTICLE{ey2,
  AUTHOR	    = {A. AAA and B. BBB and A. CCC and D. DDD},
  TITLE       = {Title2},
  YEAR        = {1968}
}

@ARTICLE{ey3,
  AUTHOR	    = {A. MMM and B. NNN},
  TITLE       = {Title3},
  YEAR        = {1968}
}

@ARTICLE{ey4,
  AUTHOR	    = {A. MMM and B. NNN},
  TITLE       = {Title4},
  YEAR        = {1968}
}

@ARTICLE{ey5,
  AUTHOR	    = {Aaa ZZZ and Bbb VVV},
  TITLE       = {Title3},
  YEAR        = {1968}
}

@ARTICLE{ey6,
  AUTHOR	    = {Abb ZZZ and Bbb VVV},
  TITLE       = {Title6},
  YEAR        = {1968}
}

@ARTICLE{ey7,
  TITLE       = {Titlea},
  YEAR        = {1968}
}

@ARTICLE{ey8,
  TITLE       = {Titlea},
  YEAR        = {1968}
}

@ARTICLE{ey9,
  TITLE       = {Titleb},
  YEAR        = {1968}
}









