Agripina Fomeni, Chamelya V.C Sene, Rozita Yusniaty Lodo, Timoteus Ajito and Timoteus Ajito 2026. Students’ Difficulties in Mastering English Vocabulary Using Duolingo at SMP IL Kapten Nasipanaf Kupang: Penelitian . Jurnal Pengabdian Masyarakat dan Riset Pendidikan. 4, 4 (Jun. 2026), 26139–26142. DOI:https://doi.org/10.31004/jerkin.v4i4.6616.