Sihombing, Y. R.; Romauli Anna Teresia Marbun; Lenni Rismayanti; Ratih Anggraeni; Octavian Ashido Nababan; Kristian Cahayani Zebua. Comparison Of Naso Faring And Oro Pharynx Swab Samples On Positivity Rate For Covid – 19 With The Reverse Transcription Method Pcr (Rt–Pcr) In The Lab. Rsud Pcr. City Padang Sidempuan. JFM 2024, 6, 106-114.