Putri, Ineke, Wahyu Widayati, and Victor Maruli Tua Tobing. 2020. “Pemerolehan Kosakata Anak Down Syndrome Berdasarkan Kelas Kata Bahasa Indonesia Di SLB C1 AKW Kumara 1 Surabaya: The Acquisition of Vocabulary in Down Syndrome Children Based on Word Classes in Indonesian Language at C1 AKW Kumara 1 Special School Surabaya”. Wacana : Jurnal Bahasa, Seni, Dan Pengajaran 4 (1):22-28. https://doi.org/10.29407/jbsp.v4i1.14783.