On page 11: "Crasmaru shows that it is NP-complete to determine the status of certain restricted forms of life-and-death problems in Go." (See the following reference.) Erik D. Demaine; Robert A. Hearn (2008-04-22). "Playing Games with Algorithms: Algorithmic Combinatorial Game Theory". arXiv:cs/0106019.
Rémi Coulom (2007). "Efficient Selectivity and Backup Operators in Monte-Carlo Tree Search". Computers and Games, 5th International Conference, CG 2006, Turin, Italy, May 29–31, 2006. Revised Papers. H. Jaap van den Herik, Paolo Ciancarini, H. H. L. M. Donkers (eds.). Springer. pp. 72–83. CiteSeerX10.1.1.81.6817. ISBN978-3-540-75537-1.