“…Ten out of the eighteen studies [ 67 , 69 , 72 , 73 , 74 , 76 , 77 , 80 , 83 , 84 ] used SDL models (columns C5, C6). In contrast, the authors of [ 68 , 70 , 71 , 75 , 78 , 79 , 81 , 82 ] and our proposed study (R19) used EDL models as the main architecture, using concatenation, fusion, or weighted sums. All of the studies [ 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 ] demonstrated three to four kinds of data source, namely, social media chat, reviews, or public communications (column C9).…”