Mohammed, Isah Kimpa, et al. “Physical Characterization and Electrical Conductivity of Li1.2Ti1.8Al0.2(PO4)3 and Li1.2Ta0.9Al1.1(PO4)3 NASICON Material”. International Journal of Integrated Engineering, vol. 10, no. 9, Jan. 2019, https://penerbit.uthm.edu.my/ojs/index.php/ijie/article/view/2380.