Melenina, F.; Ismainar, H.; Hayana, H.; Rasyid, Z. .; Sando, W. Determinants of the Application of Handwashing With Soap in the Elderly in Preventing Covid-19 at UPT PSTW Khusnul Khotimah Riau Province Social Service in 2022: Determinan Penerapan Cuci Tangan Pakai Sabun Pada Lansia Dalam Pencegahan Covid-19 Di UPT PSTW Khusnul Khotimah Dinas Sosial Provinsi Riau Tahun 2022. ORKES 2022, 1, 219-228.