Object Descriptions
Abell PN Catalogue (84)
Abell 21
Abell 85
References
- [331] Globular Clusters and Planetary Nebulae Discovered on the National Geographic Society-Palomar Observatory Sky Survey; Abell, G. O.; Publications of the Astronomical Society of the Pacific, Vol. 67, No. 397, p.258-261, August 1955; DOI:10.1086/126815; Bibcode:1955PASP...67..258A
- [332] Properties of Some Old Planetary Nebulae»; Abell, G. O.; Astrophysical Journal, vol. 144, p.259, April 1966; DOI:10.1086/148602; Bibcode:1966ApJ...144..259A