Marni Olypia Sinaga, et al. , translators. “Description of Hand Washing and Mask Wearing Knowledge During the Pandemic in Grade 4-5 School Children at Dolok Nagodang State Elementary School in 2021”. Jurnal Indah Sains Dan Klinis, vol. 3, no. 2, Aug. 2022, pp. 18-22, https://doi.org/10.52622/jisk.v3i2.50.