Salihah PR, Sahiruddin S, Degeng PDD. An Analysis of Text Readability in 9th Grade English Textbook Using FRE Formula on Readable Software. diglossia. jurnal. kaji. ilm. kebahasaan. dan. kesusastraan [Internet]. 2019 Sep. 19 [cited 2024 Nov. 22];11(1):24-33. Available from: https://journal.unipdu.ac.id/index.php/diglosia/article/view/1753