The electronic structure of the doped one-dimensional transition metal oxide Y2-xCaxBaNiO5 studied using X-ray absorptionZ. Hu, M. Knupfer, M. Kielwein, U. K. Rößler, M. S. Golden, J. Fink, F. M.F. de Groot, T. Ito, K. Oka and G. KaindlEur. Phys. J. B, 26 4 (2002) 449-453DOI: https://doi.org/10.1140/epjb/e20020113