Santy Christinawati, and Wahyu Trimastuti. “The Use of Modal Auxiliary Verbs in Covid -19 News: An Analysis of Selected News in Digital Newspaper ”. Jurnal Sastra - Studi Ilmiah Sastra, Vol. 11, no. 2, Dec. 2021, pp. 25-33, http://45.118.112.109/ojspasim/index.php/sastra/article/view/248.