Y. Firdausi, Watini, and K. Rofiah, “The Effectiveness of the Academic Program ‘A-I-U-E-O Vocal Adventure’ as an Innovation in Oral Language Learning on the Vocal Production Skills of Students with Hearing Impairments at SLB PGRI KAMAL”, Grab Kids, vol. 6, no. 1, pp. 1–6, Jan. 2026.