2019. An Analysis of Grammatical Errors in Writing Thesis Proposal of English Department Students in Mulawarman University in the Academic Year 2018/2019. E3L: Journal of English Language Teaching, Linguistics, and Literature. 2, 2 (Sep. 2019), 60–64. DOI:https://doi.org/10.30872/e3l.v2i2.1994.