Kluwer
W. Palz , G.T. Wrixon , P. Helm

Verhoef, L. A., Michiels, P.-P., Stroom, J. C., van Zolingen, R. J. C., & Sinke, W. (1989). Efficiency improvement of polycrystalline silicon solar cells by combined phosphorous- and aluminium-induced gettering. In W. Palz, G. T. Wrixon, & P. Helm (Eds.), Ninth E.C. Photovoltaic Solar Energy Conference : Proceedings of the International Conference held at Freiburg, Fed. Rep. of Germany, 25-29 September 1989 (pp. 733–736).