"Picture Thresholding Using an Iterative Selection Method". IEEE Transactions on Systems, Man, and Cybernetics. 8 (8): 630–632. 1978. doi:10.1109/TSMC.1978.4310039.
Kapur, J. N.; Sahoo, P. K.; Wong, A. K. C. (1985-03-01). "A new method for gray-level picture thresholding using the entropy of the histogram". Computer Vision, Graphics, and Image Processing. 29 (3): 273–285. doi:10.1016/0734-189X(85)90125-2.