Wong, W. , Lim, M. , Hyun, Y. , Liu, C. , Choi, S. , Kim, D. , Kwahk, K. , Kim, N.. "A Methodology for Investigating Public Opinion Using Multilevel Text Analysis". World Academy of Science, Engineering and Technology, Open Science Index 108, International Journal of Computer and Information Engineering (2015), 9(12), 2409 - 2413.