Nie, S., L. Liu, J. Liu, J. Xie, Y. Zhang, J. Xia, H. Yan, Y. Yuan, and X. Wang. “Nitrogen-Doped TiO2–C Composite Nanofibers With High-Capacity and Long-Cycle Life As Anode Materials for Sodium-Ion Batteries”. Nano-Micro Letters, vol. 10, no. 4, Oct. 2018, p. 71, doi:10.1007/s40820-018-0225-1.