Putri, I., W. . Widayati, and V. M. T. Tobing. “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, vol. 4, no. 1, Apr. 2020, pp. 22-28, doi:10.29407/jbsp.v4i1.14783.