Hubble's Planetary Nebula Gallery (PRC97-38b)
Article studies the affects of interstellar atmosphere and its effect on the development of stars. By Ronald J. Reynolds.
http://oposite.stsci.edu/pubinfo/pr/97/38/b-js.html

Planetary Nebulae Gallery
A data table with links to images.
http://www.ozemail.com.au/~mhorn/pneb.html

Planetary Nebula Sampler
A data table with links to images.
http://www.noao.edu/jacoby/pn_gallery.html

Planetary Nebula Total Observing and Data Source
images, data, observing reports and features on planetaries.
http://www.blackskies.com/index1.html

Planetary Nebulae
A short discussion, part of a web page on plasmas.
http://fusedweb.pppl.gov/CPEP/Chart_Pages/5.Plasmas/Nebula/Planetary.html

Variability of Planetary Nebula Central Stars
A short discussion, part of a web page on plasmas.
http://www.astro.psu.edu/users/rbc/res_puls.html

ARVAL Catalog of Bright Planetary Nebulas
A text table, with name, size, magnitude, area, NGC number, type, RA, dec., and visual quality.
http://www.oarval.org/PNeb.htm