S. Bajtlik (NCAC, Warsaw)
P. Życki (NCAC, Warsaw)
based on: Zoghbi et al. (arXiv:1302.1761)
A. Hypki (NCAC, Warsaw)
based on Ivanova (2013; arXiv:1301.2203)
K. Suberlak
based on i.a. Robin Ciardullo , "The Planetary Nebula Luminosity Function" (2006; on-line article)