S.-G. Luo

Chemical abundances of planetary nebulae from optical recombination lines – III. The Galactic bulge PN M 1‐42 and M 2‐36

M. Barlow, P. Storey, I. J. Danziger, 2001 .

Integrated spectrum of the planetary nebula NGC 7027

M. Barlow, X.-W. Liu, D. Péquignot, 2005, astro-ph/0507155.

Chemical abundances of planetary nebulae from optical recombination lines¿ II. Abundances derived from collisionally excited lines and optical recombination lines

Y. Liu, M. J. Barlow, S.-G. Luo, 2004 .

Chemical abundances of planetary nebulae from optical recombination lines – II. The neon abundance of NGC 7009

M. J. Barlow, S.-G. Luo, Xunchuan Liu, 2001 .