Li, Changjun, Wenlong Jia, Enbin Liu, and Xia Wu. “A MULTI-HIERARCHY GREY RELATIONAL ANALYSIS MODEL FOR NATURAL GAS PIPELINE OPERATION SCHEMES COMPREHENSIVE EVALUATION”. International Journal of Industrial Engineering: Theory, Applications and Practice 19, no. 6 (December 27, 2012). Accessed November 25, 2024. https://ijietap.journals.publicknowledgeproject.org/index.php/ijie/article/view/631.