Nina Xiong, Lu Han, Guiqin Wang, Fei Zhou, Jia Wang. 2020. “An Empirical Study on the Relationship Between 12345 Citizen Service Hotline Cases and CityGrid Management Cases -Based on Correlation Analysis and Granger Causality Analysis”. Design Engineering, September, 377 -87. https://doi.org/10.17762/de.vi.168.