Towards an improvement in the spectral description of central stars of planetary nebulae W. Weidmann, R. Gamen, D. Mast, C. Fariña, G. Gimeno, E. O. Schmidt, R. P. Ashley, L. Peralta de Arriba, P. Sowicka and I. Ordonez-Etxeberria A&A, 614 (2018) A135 Published online: 03 July 2018 DOI: 10.1051/0004-6361/201731805