WASET
    Luciana Abednego and  Cecilia Nugraheni,  A Block World Problem Based Sudoku Solver.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    August 2014, vol. 92(8). 1425 - 1429
    [viewed 11 May 2024]. Available from: https://publications.waset.org/pdf/9999168.