Ou, Jishun; Yang, Shu; Wu, Yao-Jan; An, Chengchuan; Xia, Jingxin: 'Systematic clustering method to identify and characterise spatiotemporal congestion on freeway corridors', IET Intelligent Transport Systems, 2018, 12, (8), p. 826-837, DOI: 10.1049/iet-its.2017.0355
IET Digital Library, https://digital-library.theiet.org/;jsessionid=b3phe6dr037bd.x-iet-live-01content/journals/10.1049/iet-its.2017.0355