Ma’arif, I. B., Y. Bahtiar, and M. Muthoharoh. “Designing LEEF (Learning English Easy and Fun) As Learning Media for the Seventh Grade of Junior High School”. FOSTER: Journal of English Language Teaching, Vol. 2, no. 3, Aug. 2021, pp. 372-86, doi:10.24256/foster-jelt.v2i3.50.