The evolution of planetary nebulae - II. Circumstellar environment and expansion propertiesD. Schönberner, R. Jacob, M. Steffen, M. Perinotto, R. L. M. Corradi and A. AckerA&A, 431 3 (2005) 963-978DOI: https://doi.org/10.1051/0004-6361:20041669
