Cor A. J. Hurkens Leo van Iersel Judith Keijsper Steven Kelk Leen Stougie John Tromp Prefix Reversals on Binary and Ternary Strings. 292-306 2007 conf/ab/2007 AB http://dx.doi.org/10.1007/978-3-540-73433-8_21 db/conf/ab/ab2007.html#HurkensIKKST07