Siregar, H., Nasution, A. I. L. and Qarni, W. (2026) “Effectiveness of health services through the mobile-JKN application for the elderly: A case study at the Gunung Tua BPJS health office, North Sumatra ”, Science Midwifery, 13(6), pp. 1696–1703. doi: 10.35335/midwifery.v13i6.2274.