@article{31484,
      author       = "Yokoyama, K. and 20. General Assembly IUGG - IERS Session.
                      Vienna, August 1991",
      title        = "Summary Report of the International Earth Rotation Service
                      for the Period from August 1987 through July 1991  ",
      year         = "1991",
      note         = "Liter. - 1 obr. v příl.",
}