Poole-Frenkel conduction in Al/ZrO2/SiO2/Si structures P. V. Aleskandrova, V. K. Gueorguiev, Tz. E. Ivanov and J. B. Koprinarova Eur. Phys. J. B, 52 4 (2006) 453-457 Published online: 21 August 2006 DOI: 10.1140/epjb/e2006-00335-2