Y. A. Sari, E. K. Ratnasari, S. Mutrofin, and A. Z. Arifin, “USER EMOTION IDENTIFICATION IN TWITTER USING SPECIFIC FEATURES: HASHTAG, EMOJI, EMOTICON, AND ADJECTIVE TERM”, Jurnal Ilmu Komputer dan Informasi, vol. 7, no. 1, pp. 18-23, Aug. 2014.