@Article{	  dl08ijac,
  author	= "Volker Diekert and Markus Lohrey",
  journal	= "International Journal of Algebra and Computation",
  pages		= "493--533",
  title		= "Word equations over graph products",
  volume	= "18",
  year		= "2008",
  note		= "Conference version in FSTTCS 2003",
  doi		= "10.1142/S0218196708004548"
}