Bond, Howard E. (2000). "Binarity of Central Stars of Planetary Nebulae". Asymmetrical Planetary Nebulae II: From Origins to Microstructures. 199: 115. arXiv:astro-ph/9909516. Bibcode:2000ASPC..199..115B.
Bond, Howard E. (2000). "Binarity of Central Stars of Planetary Nebulae". Asymmetrical Planetary Nebulae II: From Origins to Microstructures. 199: 115. arXiv:astro-ph/9909516. Bibcode:2000ASPC..199..115B.