et. al., Melba Rosalind. J. “Detecting Polarity Score Of The Course Feedback Text Reviews Using Customized Sentiment Lexicon”. Turkish Journal of Computer and Mathematics Education (TURCOMAT), vol. 12, no. 7, Apr. 2021, pp. 2506-15, https://turcomat.org/index.php/turkbilmat/article/view/3579.