4Sun Qian, Tang Yong. The grey relational degree measurement of city's S&T input and sustainable economic development based on the data from hunan province. 2011.
5Chi Yuan-ying, Chi Yuan-qian, Niu Dong-xiao. The grey relational degree analysis of the Jilin modem logistics and the modem service industry,2009.
6Zhang Rong, Liu Bin, Li Ye. A New Computation Model of Grey Relational Degree. Journal of Grey System,2011.
7MARTINEZ J A, MARTIN-ARNEDO J. Voltage sag studies in distribution networks Part II: Voltage sag assessment. TRANSACTIONS ON POWER DELIVERY, 2006,3 (21) : 1679-1688.
8XIAO J, GU W. Distribution system security region: defini- tion, model and security assessment, lET GENERATION TRANSMISSION & DISTRIBUTION, National Basic Research Program of China,2012,6 (10) : 1029-1035.
9U.S.Office of Electricity Delivery and Energy Reliability. Transforming electricity delivery[R]. New York: U.S. Department of Energy, 2007.