Khasanah, Uswatun. “The Implementation of Action Song in Improving Mentally Retarded (Type C1) Students’ Vocabulary Attainment”. ELT Forum: Journal of English Language Teaching 8, no. 2 (November 30, 2019): 152-157. Accessed November 22, 2024. http://journal.unnes.ac.id/sju/elt/article/view/32026.