@Article{	  dixsch00,
  author	= {J\"{u}rgen Dix and Karl Schlechta},
  title		= {Explaining {U}pdates by minimal Sums},
  journal	= {Theoretical Computer Science},
  year		= {2001},
  volume	= {266},
  number	= {1-2},
  pages		= {819--838}
}