Frank Hoffmann. One Pebble Does Not Suffice to Search Plane Labyrinths. In Ferenc Gécseg, editor, Fundamentals of Computation Theory, FCT 81, Proceedings of the 1981 International FCT-Conference, Szeged, Hungary, August 24-28, 1981. Volume 117 of Lecture Notes in Computer Science, pages 433-444, Springer, 1981.
Abstract is missing.