Ionic-to-electronic conductivity of glasses in the P2O5-V2O5-ZnO-Li2O system A. Langar, N. Sdiri, H. Elhouichet and M. Ferid Eur. Phys. J. Plus, 131 12 (2016) 421 Published online: 06 December 2016 DOI: 10.1140/epjp/i2016-16421-y