“…As one can see, to study the sentiment analysis in Latvian, most authors of the articles under survey created their corpora from Twitter [14], [15], [17], [19], [20]. Papers on the sentiment analysis in Russian are more diverse: apart from Twitter [23], authors use news articles [25], [28], [30] and reviews [24], [26], [29]. In the Latvian language, human annotated corpora are small, even if combined together, so researchers are either using noisy-labelling or lexicon-based methods, which do not require a large annotated corpus.…”