Hung, Van, Vu Thi Minh Nguyet, Bui Van Quynh, & Ha Tung Lam. " Application of Principal Component Analysis in Determining the Hydrogeochemistry Characteristics of Karst Water in Bac Kan and Cao Bang." VNU Journal of Science: Earth and Environmental Sciences [Online], 40.2 (2024): n. pag. Web. 24 Nov. 2024