@InProceedings{	  HertrampfW91csl,
  title		= "Interactive Proof Systems: Provers, Rounds, and Error
		  Bounds",
  year		= "1991",
  volume	= "533",
  pages		= "261--273",
  publisher	= "Springer",
  address	= "Berlin",
  series	= "Lecture Notes in Computer Science",
  booktitle	= "Computer science logic ({H}eidelberg, 1990)",
  doi		= "10.1007/3-540-54487-9_63",
  author	= "Hertrampf, Ulrich and Wagner, Klaus"
}