@article {1969ApJ...155...27A,
	title = {Calculations of Ionization Equilibria for Oxygen, Neon, Silicon, and Iron},
	journal = {\apj},
	volume = {155},
	year = {1969},
	pages = {27},
	doi = {10.1086/149844},
	author = {Allen, J.~W. and Dupree, A.~K.}
}
