Hardini, C.P. and Handayani, S. 2023. USING NUMBERED HEADS TOGETHER TO IMPROVE STUDENTS’ VOCABULARY LEARNING OUTCOMES: A Classroom Action Research with The Students of SMP Islam Al - Hadi Sukoharjo. English Research Journal : Journal of Education, Language, Literature, Arts and Culture. 6, 2 (Jul. 2023). DOI:https://doi.org/10.33061/erj.v6i2.6124.