Silalahi, D. E. “The Effect of Using Mind Mapping Technique in Writing Descriptive Text at the First Year Students of SMA Negeri 4 Pematangsiantar”. Journal of English Teaching As a Foreign Language, vol. 2, no. 1, June 2016, pp. 1-6, https://ejournal.uhn.ac.id/index.php/jetafl/article/view/156.