Computational Complexity of Cast Puzzles. - Chuzo Iwamoto; Kento Sasaki; Kenji Nishio; Kenichi Morita (ISAAC, 2009)

NP-Hard and k-EXPSPACE-Hard Cast Puzzles. - Chuzo Iwamoto; Kento Sasaki; Kenji Nishio; Kenichi Morita (IEICE Trans. Inf. Syst., 2010)