PT Unknown AU Il'in, K Siegel, M Semenov, A Engel, A Hübers, H Hollmann, E Gol'tsman, G Voronov, B TI Thickness dependence of superconducting properties of ultrathin Nb and NbN films SE AKF-Frühjahrstagung PY 2004 DE Nb; NbN films; has potential plagiarism ER