“…LSTM and BiLSTM, as SDL or as HDL, were the main approaches used in studies [ 58 , 60 , 62 , 63 ], while studies [ 59 , 64 ] used statistical ML algorithms, and the authors of [ 65 ] implemented decision trees with pruning for classification. Four out of the nine studies [ 58 , 60 , 61 , 62 , 63 ] used SDL models (columns C5, C6). In contrast, the authors of [ 64 , 65 , 66 ] used EDL models as the main architecture through the use of stacking, feature extraction, or max voting.…”