D A N I E L R A T N E R A N D M A N F R E D W A R M

The ( n 2-1 )-Puzzle and Related Relocation Problems

D A N I E L R A T N E R A N D M A N F R E D W A R M, D. A N I E L R A T N E R A N D M A N F R E D W A R M, 2008 .