Prevalence of smoking among health science students in Vietnam in 2018 and associated factors: A cross-sectional study oleh Pham Tien Nam, Pham Thanh Tung, Nguyen Hanh Dung, Duong Hoang An, Bui Dang The Anh, Quan Bich Diep, Kim Bao Giang, Dang Huong Giang, Ngo Thi Thu Hien, Pham Ngoc Hung, Nguyen Thi Thanh Huong, Bui Phuong Linh, Dao Thi Dieu Linh, Nguyen Xuan Long, Hoang Gia Thu, Duong Viet Tuan, Nguyen Huu Tu, Hoang Van Minh