Tran, Tap, Khiem Do, Nguyen La, and Tuyet Luu. 2018. “Study on the Structure of Polymer Electrolyte Membrane Using Small Angle X-Ray Scattering and Positron Annihilation Spectroscopy”. Science & Technology Development Journal: Natural Sciences 1 (6), 197-205. https://doi.org/https://doi.org/10.32508/stdjns.v1i6.630.