1. Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi 100000, Vietnam
2. Tay Nguyen University, 567 Le Duan, Buon Me Thuat 630000, Daklak, Vietnam
3. College of Education, Vinh University, 182 Le Duan, Vinh 460000, Vietnam
4. Institute for Technology of Radioactive and Rare Elements, 48 Lang Ha, Hanoi 100000, Vietnam
5. Thanh Do University, QL32, Kim Chung, Hoai Duc, Hanoi 13200, Vietnam