Cox, J. L., S. Lucci, and T. Pay. “Effects of Dynamic Variable - Value Ordering Heuristics on the Search Space of Sudoku Modeled As a Constraint Satisfaction Problem”. Inteligencia Artificial, vol. 22, no. 63, Jan. 2019, pp. 1-15, doi:10.4114/intartif.vol22iss63pp1-15.