Nguyen, Hang Khanh Le, Son Vu Nguyen, Phuong Mai Vu Hoang, Thanh Thi Le, Huong thi Thu Tran, Long Hai Pham Nguyen, Thai Quang Pham, et al. 2021. “Virological Characteristics of Cases of COVID-19 in Northern Viet Nam, January–May 2020”. Western Pacific Surveillance and Response 12 (4). https://doi.org/10.5365/wpsar.2021.12.4.833.