Wolfe, David (2002). Nowakowski, Richard J. (ed.). "Go endgames are PSPACE-hard"(PDF). More Games of No Chance, Mathematical Sciences Research Institute Publications 42: 125–136. Archived from the original(PDF) on 2017-08-10. Retrieved 2016-07-09.
Wolfe, David (2002). Nowakowski, Richard J. (ed.). "Go endgames are PSPACE-hard"(PDF). More Games of No Chance, Mathematical Sciences Research Institute Publications 42: 125–136. Archived from the original(PDF) on 2017-08-10. Retrieved 2016-07-09.