Sihombing, Agustina, et al. “An Analysis of Grammatical Errors in Advertising Slogan”. INTERACTION: Jurnal Pendidikan Bahasa, vol. 9, no. 2, Oct. 2022, pp. 257-6, https://e-journal.unimudasorong.ac.id/index.php/interactionjournal/article/view/2460.