D.  Shan and Yang, Z., ?Hierarchical clustering analysis method based on the grid with obstacle space?, Journal of Digital Information Management, vol. 11, no. 1, pp. 76 - 82, 2013.

Z.  Yang and Zhang, L., ?Information sharing in supply chain: A review?, Journal of Digital Information Management, vol. 11, no. 2, pp. 125 - 130, 2013.