Nasution, Z., G. Sigalingging, M. Ginting, and A. Gulo. “Hubungan Pengetahuan Lansia Dengan Status Vaksinasi Covid-19”. Health Information : Jurnal Penelitian, vol. 15, no. 1, July 2023, p. e969, https://myjurnal.poltekkes-kdi.ac.id/index.php/hijp/article/view/969.